Catalyst system for polymerization of an olefin

ABSTRACT

The present invention relates to a process for the preparation of a catalyst system suitable for olefin polymerization wherein the external electron donor is n-propyltriethoxysilane, and a catalyst system obtained or obtainable by said process. The invention also relates to a process for preparing a polyolefin using said catalyst system. The invention further relates to a polyolefin, in particular polyprolyene, obtainable by such a process, and shaped articles manufactured from such a polymer. The polymers produced using the catalyst system exhibit low volatiles and therefore have a reduced environmental and health impact.

The present invention relates to a process for the preparation of acatalyst system suitable for olefin polymerization, said catalyst systemcomprising an external donor. The invention further relates to acatalyst system obtained or obtainable by said process. The inventionalso relates to a process for preparing a polyolefin using said catalystsystem and to a polyolefin obtained or obtainable by such a process. Theinvention also relates to a propylene-based polymer. In addition, theinvention relates to a shaped article from said polyolefin.

Catalyst systems and their components that are suitable for preparing apolyolefin are generally known. One type of such catalysts are generallyreferred to as Ziegler-Natta catalysts. The term “Ziegler-Natta” isknown in the art and it typically refers to catalyst systems comprisinga transition metal-containing solid catalyst compound (also typicallyreferred to as a procatalyst); an organometallic compound (alsotypically referred to as a co-catalyst) and optionally one or moreelectron donor compounds (e.g. external electron donors).

The transition metal-containing solid catalyst compound comprises atransition metal halide (e.g. titanium halide, chromium halide, hafniumhalide, zirconium halide or vanadium halide) supported on a metal ormetalloid compound (e.g. a magnesium compound or a silica compound). Anoverview of such catalyst types is for example given by T. Pullukat andR. Hoff in Catal. Rev.—Sci. Eng. 41, vol. 3 and 4, 389-438, 1999. Thepreparation of such a procatalyst is for example disclosed in WO96/32427A1.

WO 2013/124063 discloses a dicarbonate compound and the use thereof asinternal donor. WO 01/23441 discloses a process for the preparation of acatalyst component for the polymerization of olefins. WO 2011/106497discloses halogenated amide ester and the use thereof as internaldonors. U.S. Pat. No. 5,567,665 discloses a shape-shifted magnesiumalkoxide component for olefin polymerization. WO 2011/106500 disclosesamide esters and the use thereof as internal donors. EP 0 799 839discloses the preparation of a propylene homopolymer by radiationvisbreaking in a multistage fluidized bed reactor. EP 1 717 269discloses α-olefin homo- or copolymers having a certain relation betweenthe MFR and the oligomer content. JP 2008 106889 discloses apolypropylene injection molded product.

Polyolefins are known to emit volatiles. The volatile fraction of apolymer is associated with the content of oligomers with a relativelylow molecular weight, the so-called oligomer content. The emission ofvolatiles may eventually lead to detoriation of material properties.Also, the emissions are associated with environmental risks and healthrisks.

Hence, there is an ongoing need in the industry to reduce the volatilefraction in polymers.

It is an object of the invention to provide an improved catalyst systemfor the polymerization of olefins and to a process to prepare such asystem.

It is a further object of the present invention to provide a procatalystwhich shows better performance, when used in a catalyst system for thepolymerization of olefins, especially with respect to reducing avolatile fraction in the polymer product.

One or more of the aforementioned objects of the present invention areachieved by the various aspects of the present invention whereinn-propyltriethoxysilane (nPTES) is used as an external electron donor.

It has surprisingly been found by the present inventors that a catalystsystem having the external donor according to the present inventionshows a lower emission.

In a first aspect, the present invention relates to a process for thepreparation of a catalyst system suitable for olefin polymerization,said process comprising the steps of: providing a magnesium-basedsupport;

-   -   optionally activating said magnesium-based support;    -   contacting said magnesium-based support with a Ziegler-Natta        type catalytic species, and optionally one or more internal        electron donors to yield a procatalyst, and    -   contacting said procatalyst with a co-catalyst and at least one        external donor;    -   wherein the at least one external electron donor being a        compound having a structure according to Formula IV:        (R⁹²)Si(OR⁹³)₃, wherein, the R⁹² and R⁹³ groups are each        independently a linear, branched or cyclic, substituted or        unsubstituted alkyl having between 1 and 10 carbon atoms,        preferably a linear unsubstituted alkyl having between 1 and 8        carbon atoms wherein R⁹² is n-propyl and R⁹³ are each ethyl,        being n-propyltriehtoxysilanse (nPTES).

In an embodiment of said first aspect, the process comprises the stepsof i) preparing a magnesium-based support by heating a carbonatedmagnesium compound of the formula MgR′R″xCO₂ wherein R′ is an alkoxideor aryloxide group, R″ is an alkoxide group, aryloxide group or halogen,and x has a value between about 0.1 and 2.0 to a temperature above 100°C. for a period of time sufficient to cause complete loss of CO₂;

ii) contacting the resulting product with a halide of tetravalenttitantium as the Ziegler-Natta type catalytic species in the presence ofa halohydrocarbon and an internal electron donor; andiii) contacting the resulting halogenated product with a tetravalenttitanium halide; and contacting the product thus obtained with nPTES asthe external donor.

In another embodiment of said aspect, the process comprises the step ofpreparing a magnesium-based support by halogenating a magnesium compoundof the formula MgR′R″, wherein R′ and R″ are alkoxide groups containingfrom 1 to 8 carbon atoms, with titanium tetrachloride, in the presenceof (1) an aromatic halohydrocarbon containing from 6 to 12 carbon atomsand from 1 to 2 halogen atoms and (2) a polycarboxylic acid esterderived from a branched or unbranched monohydric alcohol containing from1 to 12 carbon atoms, and a monocyclic or polycyclic aromatic compoundcontaining from 8 to 20 carbon atoms and two carboxyl groups which areattached to ortho carbon atoms of the ring structure and contacting theproduct thus obtained with nPTES as the external donor.

In another embodiment of said aspect, the process comprises the steps ofpreparing the magnesium-based support by forming a solution of amagnesium-containing species from a magnesium carbonate or a magnesiumcarboxylate, precipitating solid particles from suchmagnesium-containing solution by treatment with a transition metalhalide and an organosilane having a formula: RnSiR′₄″n, wherein n=0 to 4and wherein R is hydrogen or an alkyl, a haloalkyl or aryl radicalcontaining one to about ten carbon atoms or a halosilyl radical orhaloalkylsilyl radical containing one to about eight carbon atoms, andR′ is OR or a halogen, and reprecipitating such solid particles from amixture containing a cyclic ether and contacting the product thusobtained with nPTES as the external donor.

In another embodiment of said aspect, the process comprises the stepsof:

-   -   A) providing said procatalyst obtainable via a process        comprising the steps of:        -   i) contacting a compound R⁴ _(z)MgX⁴ _(2-z) with an alkoxy-            or aryloxy-containing silane compound to give a first            intermediate reaction product, being a solid Mg(OR¹)_(x)X¹            _(2-x), wherein: R⁴ is the same as R¹ being a linear,            branched or cyclic hydrocarbyl group independently selected            from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or            alkylaryl groups, and one or more combinations thereof;            wherein said hydrocarbyl group may be substituted or            unsubstituted, may contain one or more heteroatoms and            preferably has between 1 and carbon atoms; X⁴ and X¹ are            each independently selected from the group of consisting of            fluoride (F—), chloride (Cl—), bromide (Br—) or iodide (I—),            preferably chloride; z is in a range of larger than 0 and            smaller than 2, being 0<z<2;        -   ii) optionally contacting the solid Mg(OR¹)_(x)X_(2-x)            obtained in step i) with at least one activating compound            selected from the group formed of activating electron donors            and metal alkoxide compounds of formula            M¹(OR²)_(v-w)(OR³)_(w) or M²(OR²)_(v-w)(R³)_(w), to obtain a            second intermediate product; wherein M¹ is a metal selected            from the group consisting of Ti, Zr, Hf, Al or Si; M² is a            metal being Si; v is the valency of M¹ or M²; R² and R³ are            each a linear, branched or cyclic hydrocarbyl group            independently selected from alkyl, alkenyl, aryl, aralkyl,            alkoxycarbonyl or alkylaryl groups, and one or more            combinations thereof; wherein said hydrocarbyl group may be            substituted or unsubstituted, may contain one or more            heteroatoms, and preferably has between 1 and 20 carbon            atoms;        -   iii) contacting the first or second intermediate reaction            product, obtained respectively in step i) or ii), with a            halogen-containing Ti-compound and optionally an internal            electron donor to obtain said procatalyst;    -   B) contacting said procatalyst with a co-catalyst and at least        one external electron donor being nPTES.

In another embodiment of said aspect, the process is essentiallyphthalate free.

In another embodiment of said aspect, the internal donor is selectedfrom aminobenzoates represented by formula (XI):

wherein:R⁸⁰, R⁸¹, R⁸², R⁸³, R⁸⁴, R⁸⁵, and R⁸⁶ are independently selected from agroup consisting of hydrogen, C₁-C₁₀ straight and branched alkyl; C₃-C₁₀cycloalkyl; C₆-C₁₀ aryl; and C₇-C₁₀ alkaryl and aralkyl group; whereinR⁸¹ and R⁸² is each a hydrogen atom and R⁸³, R⁸⁴, R⁸⁵ and R⁸⁶ areindependently selected from a group consisting of C₁-C₁₀ straight andbranched alkyl; C₃-C₁₀ cycloalkyl; C₆-C₁₀ aryl; and C₇-C₁₀ alkaryl andaralkyl group, preferably from C₁-C₁₀ straight and branched alkyl andmore preferably from methyl, ethyl, propyl, isopropyl, butyl, t-butyl,phenyl group; wherein when one of R⁸³ and R⁸⁴ and one of R⁸⁵ and R⁸⁶ hasat least one carbon atom, then the other one of R⁸³ and R⁸⁴ and of R⁸⁵and R⁸⁶ is each a hydrogen atom; wherein R⁸⁷ is selected from a groupconsisting of hydrogen, methyl, ethyl, propyl, isopropyl, butyl,t-butyl, phenyl, benzyl, substituted benzyl and halophenyl group; andwherein R⁸⁰ is selected from the group consisting of C₆-C₁₀ aryl; andC₇-C₁₀ alkaryl and aralkyl group; preferably, R⁸⁰ is substituted orunsubstituted phenyl, benzyl, naphthyl, ortho-tolyl, para-tolyl oranisol group, and more preferably R⁸⁰ is phenyl.

In another embodiment of said aspect, the internal electron donor isselected from the group consisting of4-[benzoyl(methyl)amino]pentan-2-yl benzoate;2,2,6,6-tetramethyl-5-(methylamino)heptan-3-ol dibenzoate; 4-[benzoyl(ethyl)amino]pentan-2-yl benzoate, 4-(methylamino)pentan-2-yl bis(4-methoxy)benzoate);3-[benzoyl(cyclohexyl)amino]-1-phenylbutylbenzoate;3-[benzoyl(propan-2-yl)amino]-1-phenylbutyl;4-[benzoyl(methyl)amino]-1,1,1-trifluoropentan-2-yl;3-(methylamino)-1,3-diphenylpropan-1-ol dibenzoate;3-(methyl)amino-propan-1-ol dibenzoate;3-(methyl)amino-2,2-dimethylpropan-1-ol dibenzoate, and4-(methylamino)pentan-2-yl-bis (4-methoxy)benzoate).

In yet another embodiment of said aspect, the internal electron donor isactivated by an activator, preferably wherein the activator is abenzamide according to formula X,

wherein: R⁷⁰ and R⁷¹ are each independently selected from hydrogen or analkyl, preferably an alkyl, more preferably having between 1 and 6carbon atoms; R⁷², R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ are each independently selectedfrom hydrogen, a heteroatom such as a halide, or a hydrocarbyl groupselected e.g. from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl oralkylaryl groups, and one or more combinations thereof, whereinpreferably the activator is N,N-dimethylbenzamide, wherein preferablythe benzamide according to formula X is present in the procatalyst in anamount from 0.1 to 4 wt. % as determined using HPLC, for example from0.1 to 3.5 wt. %, for example from 0.1 to 3 wt. %, for example from 0.1to 2.5 wt. %, for example from 0.1 to 2.0 wt. %, for example from 0.1 to1.5 wt. %.

In a second aspect, the present invention relates to a catalyst systemobtained or obtainable by the process as described herein.

In another aspect, the present invention relates to a process forpreparing a polyolefin by contacting at least one olefin, preferablypolypropylene or a mixture of propylene and ethylene with the catalystsystem as described herein.

In yet another aspect, the present invention relates to a polyolefinobtained or obtainable by the process as described herein.

In yet another aspect, the invention relates to a propylene-basedpolymer, such as propylene homopolymer or propylene-olefin copolymer.

In yet another aspect, the invention relates to a propylene-ethylenecopolymer, for example having an ethylene content based onpropylene-ethylene copolymer in the range from 1 to 10 wt. %, preferablyin the range from 1 to 8, more preferably in the range from 1 to 5 wt.%.

In yet another aspect, the invention relates to heterophasic propylenecopolymers.

In another aspect, the present invention relates to propylene-basedpolymers having a melt flow index in the range from 30 to 1000, forexample from 40 to 500 as determined according to ISO 1133: 2005 at 230°C. with 2.16 kg load.

In another aspect, the present invention relates to propylene-basedpolymers having a ratio of the oligomer content in ppm to the log(meltflow index) of less than 1650, for example of less than 1550. Theoligomer content is measured using the method as disclosed in thedescription.

In another aspect, the present invention relates to propylene-basedpolymers having at log (MFR)=2.1, a oligomer content of less than 1850ppm, wherein this is determined by making a calibration line of theoligomer content of the polymer versus the log(MFR), wherein the polymerof the calibration line is produced using a Ziegler Natta catalyst andthe same external donor.

In yet another aspect, the invention relates to a propylene-basedpolymer, such as propylene homopolymer or propylene-olefin copolymer,for example propylene-ethylene copolymer, for example having an ethylenecontent based on propylene-ethylene copolymer in the range from 1 to 10wt. %, for example in the range from 1 to 8, for example in the rangefrom 1 to 5 wt. %; or heterophasic propylene copolymers,

-   -   having a melt flow index in the range from 30 to 1000, for        example from 40 to 500 as determined according to the method        discussed below;    -   a ratio of the oligomer content in ppm to the log(melt flow        index) of less than 1650, for example of less than 1550, wherein        the oligomer content is measured according to the method        discussed below.

In another aspect, the invention relates to a shaped article comprisingthe polyolefin as described herein. These aspects and embodiments willbe described in more detail below.

The procatalyst according to the present invention exhibits excellentyield in catalyst preparation, and when used in the preparation ofpolyolefins, in particular for polypropylene and polypropylene/ethylenecopolymers. In addition, the catalyst system according to the presentinvention produces polyolefins with a reduced volatile fraction whencompared to known catalyst systems. The polyolefins prepared using thecatalyst system as described herein, as well as shaped productsmanufactured from such are therefore have diminished health andenvironmental risks compared to polyolefins prepared using knowncatalyst systems. The polyolefins also show a lower material detoriationover time when compared to similar polyolefins prepared using adifferent catalyst system.

DEFINITIONS

The following definitions are used in the present description and claimsto define the stated subject matter. Other terms not cited below aremeant to have the generally accepted meaning in the field.

“Ziegler-Natta catalyst” as used in the present description means: atransition metal-containing solid catalyst compound comprises atransition metal halide selected from titanium halide, chromium halide,hafnium halide, zirconium halide, and vanadium halide, supported on ametal or metalloid compound (e.g. a magnesium compound or a silicacompound).

“Ziegler-Natta catalytic species” or “catalytic species” as used in thepresent description means: a transition metal-containing speciescomprises a transition metal halide selected from titanium halide,chromium halide, hafnium halide, zirconium halide and vanadium halide.

“internal donor” or “internal electron donor” or “ID” as used in thepresent description means: an electron-donating compound containing oneor more atoms of oxygen (O) and/or nitrogen (N). This ID is used as areactant in the preparation of a solid procatalyst. An internal donor iscommonly described in prior art for the preparation of a solid-supportedZiegler-Natta catalyst system for olefins polymerization; i.e. bycontacting a magnesium-containing support with a halogen-containing Ticompound and an internal donor.

“external donor” or “external electron donor” or “ED” as used in thepresent description means: an electron-donating compound used as areactant in the polymerization of olefins.

An ED is a compound added independent of the procatalyst. It is notadded during procatalyst formation. It contains at least one functionalgroup that is capable of donating at least one pair of electrons to ametal atom. The ED may influence catalyst properties, non-limitingexamples thereof are affecting the stereoselectivity of the catalystsystem in polymerization of olefins having 3 or more carbon atoms,hydrogen sensitivity, ethylene sensitivity, randomness of co-monomerincorporation and catalyst productivity.

“activator” as used in the present description means: anelectron-donating compound containing one or more atoms of oxygen (O)and/or nitrogen (N) which is used to during the synthesis of theprocatalyst prior to or simultaneous with the addition of an internaldonor.

“activating compound” as used in the present description means: acompound used to activate the solid support prior to contacting it withthe catalytic species.

“modifier” or “Group 13- or transition metal modifier” as used in thepresent description means: a metal modifier comprising a metal selectedfrom the metals of Group 13 of the IUPAC Periodic Table of elements andtransition metals. Where in the description the terms metal modifier ormetal-based modifier is used, Group 13- or transition metal modifier ismeant.

“procatalyst” and “catalyst component” as used in the presentdescription have the same meaning: a component of a catalyst compositiongenerally comprising a solid support, a transition metal-containingcatalytic species and optionally one or more internal donor.

“halide” as used in the present description means: an ion selected fromthe group of: fluoride (F—), chloride (Cl—), bromide (Br—) or iodide(I—).

“halogen” as used in the present description means: an atom selectedfrom the group of: fluorine (F), chlorine (Cl), bromine (Br) or iodine(I).

“Heteroatom” as used in the present description means: an atom otherthan carbon or hydrogen. However, as used herein—unless specifiedotherwise, such as below,—when “one or more hetereoatoms” is used one ormore of the following is meant: F, Cl, Br, I, N, O, P, B, S or Si.

“heteroatom selected from group 13, 14, 15, 16 or 17 of the IUPACPeriodic Table of the Elements” as used in the present descriptionmeans: a hetero atom selected from B, Al, Ga, In, TI [Group 13], Si, Ge,Sn, Pb [Group 14], N, P, As, Sb, Bi [Group 15], 0, S, Se, Te, Po [Group16], F, Cl, Br, I, At [Group 17].

“hydrocarbyl” as used in the present description means: is a substituentcontaining hydrogen and carbon atoms, or linear, branched or cyclicsaturated or unsaturated aliphatic radical, such as alkyl, alkenyl,alkadienyl and alkynyl; alicyclic radical, such as cycloalkyl,cycloalkadienyl cycloalkenyl; aromatic radical, such as monocyclic orpolycyclic aromatic radical, as well as combinations thereof, such asalkaryl and aralkyl.

“substituted hydrocarbyl” as used in the present description means: is ahydrocarbyl group that is substituted with one or more non-hydrocarbylsubstituent groups. A non-limiting example of a non-hydrocarbylsubstituent is a heteroatom. Examples are alkoxycarbonyl (viz.carboxylate) groups. When in the present description “hydrocarbyl” isused it can also be “substituted hydrocarbyl”, unless stated otherwise.

“alkyl” as used in the present description means: an alkyl group being afunctional group or side-chain consisting of carbon and hydrogen atomshaving only single bonds. An alkyl group may be straight or branched andmay be un-substituted or substituted. It may or may not containheteroatoms, such as oxygen (O), nitrogen (N), phosphorus (P), silicon(Si) or sulfur (S). An alkyl group also encloses aralkyl groups whereinone or more hydrogen atoms on the alkyl group been replaced by arylgroups.

“aryl” as used in the present description means: an aryl group being afunctional group or side-chain derived from an aromatic ring. An arylgroup and may be un-substituted or substituted with straight or branchedhydrocarbyl groups. It may or may not contain heteroatoms, such asoxygen (O), nitrogen (N), phosphorus (P), silicon (Si) or sulfur (S). Anaryl group also encloses alkaryl groups wherein one or more hydrogenatoms on the aromatic ring have been replaced by alkyl groups.

“alkoxide” or “alkoxy” as used in the present description means: afunctional group or side-chain obtained from a alkyl alcohol. It consistof an alkyl bonded to a negatively charged oxygen atom.

“aryloxide” or “aryloxy” or “phenoxide” as used in the presentdescription means: a functional group or side-chain obtained from anaryl alcohol. It consist of an aryl bonded to a negatively chargedoxygen atom.

“Grignard reagent” or “Grignard compound” as used in the presentdescription means: a compound or a mixture of compounds of formula R⁴_(z)MgX⁴ _(2-z) (R⁴, z, and X⁴ are as defined below) or it may be acomplex having more Mg clusters, e.g. R₄Mg₃Cl₂.

“polymer” as used in the present description means: a chemical compoundcomprising repeating structural units, wherein the structural units aremonomers.

“olefin” as used in the present description means: an alkene.

“olefin-based polymer” or “polyolefin” as used in the presentdescription means: a polymer of one or more alkenes.

“propylene-based polymer” as used in the present description means: apolymer of propylene and optionally a comonomer.

“polypropylene” as used in the present description means: a polymer ofpropylene.

“copolymer” as used in the present description means: a polymer preparedfrom two or more different monomers.

“monomer” as used in the present description means: a chemical compoundthat can undergo polymerization.

“thermoplastic” as used in the present description means: capable ofsoftening or fusing when heated and of hardening again when cooled.

“polymer composition” as used in the present description means: amixture of either two or more polymers or of one or more polymers andone or more additives.

“M_(w)” and “M_(n)” in the context of the present invention means theratio of the weight average molecular weight M_(w) and the numberaverage molecular weight M_(n) of a sample, as measured according toASTM D6474-12.

“PDI” in the context of the present invention means the ratio of theweight average molecular weight M_(w) and the number average molecularweight M_(n) of a sample, as measured according to ASTM D6474-12. Asused herein, the terms “PDI” and “polydispersity index” areinterchangeable.

“MWD” in the context of the present invention means distribution of themolecular weight of a sample, as represented by the ratio of the weightaverage molecular weight M_(w) and the number average molecular weightM_(n) of a sample as measured according to ASTM D6474-12. As usedherein, the terms “MWD” and “molecular weight distribution” areinterchangeable.

“XS” as used in the present description means: the xylene solublefraction in terms of percentage of polymer that does not precipitate outupon cooling of a polymer solution in xylene, said polymer solutionhaving been subjected to reflux conditions, down from the refluxtemperature, which equals the boiling temperature of xylene, to 25° C.XS is measured according to ASTM D5492-10. As used herein, the terms“XS” and “xylene soluble fraction” are interchangeable.

“polymerization conditions” as used in the present description means:temperature and pressure parameters within a polymerization reactorsuitable for promoting polymerization between the catalyst compositionand an olefin to form the desired polymer. These conditions depend onthe type of polymerization used.

“production rate” or “yield” as used in the present description means:the amount of kilograms of polymer produced per gram of catalystcomposition consumed in the polymerization reactor per hour, unlessstated otherwise.

“MFR” as used in the present description means the melt mass-flow rateas measured according to ISO 1133:2005, at 230° C. under a load of 2.16kg. As used herein, the terms “MFR”, “melt flow rate” and “meltmass-flow rate” are interchangeable.

Unless stated otherwise, when it is stated that any R group is“independently selected from” this means that when several of the same Rgroups are present in a molecule they may have the same meaning of theymay not have the same meaning. For example, for the compound R₂M,wherein R is independently selected from ethyl or methyl, both R groupsmay be ethyl, both R groups may be methyl or one R group may be ethyland the other R group may be methyl.

The present invention is described below in more detail. All embodimentsdescribed with respect to one aspect of the present invention are alsoapplicable to the other aspects of the invention, unless otherwisestated.

As stated above, the external donor nPTES according to the presentinvention shows a better result with respect to emission, in other wordshas a lower emission.

The present inventors have observed that the catalyst performance hasbeen improved by measuring the amount of volatiles in the polyolefin,and comparing this with polyolefins prepared by other catalyst systemshaving a comparable melt flow rate (MFR). Polymers having a relativelyhigh melt flow rate typically have a highter volatile content comparedto polymers having a low flow.

In particular, nPTES as external donor results in materials with loweroligomer content compared to materials with similar MFR-values, madeusing other donors. In particular, polypropylene homopolymers havinglower emissions may be produced using the catalyst system as describedherein.

One of the functions of an external donor compound is to affect thestereoselectivity of the catalyst system in polymerization of olefinshaving three or more carbon atoms. Therefore it may be also referred toas a selectivity control agent.

Mixtures of external donors may be present and may include from about0.1 mol. % to about 99.9 mol. % of a first external donor, nPTES, andfrom about 99.9 mol. % to about 0.1 mol. % of either a second or theadditional alkoxysilane external donor disclosed below. Moreover,mixtures of nPTES with other external donors may be used. In anembodiment, nPTES is the only external donor used.

The aluminum/external donor molar ratio in the polymerization catalystsystem preferably is between 0.1 and 200; more preferably between 1 and100. In a Ti-based catalyst, the Si/Ti molar ratio in the catalystsystem can range from 0.1 to 40, preferably from 0.1 to 20, even morepreferably from 1 to 20 and most preferably from 2 to 10.

Alkyl-alkoxysilanes according to Formula IV may be used as additionalexternal donors. nPTES, the first external donor is also according toFormula IV.

(R⁹²)Si(OR⁹³)₃  Formula IV

The R⁹² and R⁹³ groups are each independently an alkyl having between 1and 10 carbon atoms. Said alkyl group may be linear, branched or cyclic.Said alkyl group may be substituted or unsubstituted. Preferably, saidhydrocarbyl group has between 1 and 8 carbon atoms, even more preferablybetween 1 and 6 carbon atoms, even more preferably between 2 and 4carbon atoms. Preferably, all three R⁹³ groups are the same. PreferablyR⁹³ is methyl or ethyl. Preferably R⁹² is ethyl or propyl, morepreferably n-propyl.

Typical external donors known in the art (for instance as disclosed indocuments WO2006/056338A1, EP1838741B1, U.S. Pat. No. 6,395,670B1,EP398698A1, WO96/32426A) are organosilicon compounds having generalformula Si(OR^(a))_(4-n)R^(b) _(n), wherein n can be from 0 up to 2, andeach R^(a) and R^(b), independently, represents an alkyl or aryl group,optionally containing one or more hetero atoms for instance O, N, S orP, with, for instance, 1-20 carbon atoms; such as n-propyltrimethoxysilane (nPTMS), n-propyl triethoxysilane (nPEMS), diisobutyldimethoxysilane (DiBDMS), t-butyl isopropyl dimethyxysilane (tBiPDMS),cyclohexyl methyldimethoxysilane (CHMDMS), dicyclopentyl dimethoxysilane(DCPDMS) or di(iso-propyl) dimethoxysilane (DiPDMS). These may also beused as second external donor, in addition to nPTES.

The present invention is related to Ziegler-Natta type catalyst system.A Ziegler-Natta type procatalyst for use in a Ziegler-Natta typecatalyst system generally comprising a solid support, a transitionmetal-containing catalytic species and optionally one or more internaldonors. The present invention moreover relates to a catalyst systemcomprising a Ziegler-Natta type procatalyst, a co-catalyst and nPTES asthe external electron donor. The term “Ziegler-Natta” is known in theart.

The transition metal-containing solid catalyst compound comprises atransition metal halide (e.g. titanium halide, chromium halide, hafniumhalide, zirconium halide, vanadium halide) supported on a metal ormetalloid compound (e.g. a magnesium compound or a silica compound).

Specific examples of several types of Ziegler-Natta catalyst asdisclosed below.

Preferably, the present invention is related to a so-called TiNocatalyst. It is a magnesium-based supported titanium halide catalystoptionally comprising one or more internal donors. Procatalyst III ofthe Examples specifies the process to prepare a TiNO procatalyst.

EP 1 273 595 of Borealis Technology discloses a process for producing anolefin polymerization procatalyst in the form of particles having apredetermined size range, said process comprising: preparing a solutiona complex of a Group IIa metal and an electron donor by reacting acompound of said metal with said electron donor or a precursor thereofin an organic liquid reaction medium; reacting said complex, insolution, with at least one compound of a transition metal to produce anemulsion the dispersed phase of which contains more than 50 mol. % ofthe Group Ila metal in said complex; maintaining the particles of saiddispersed phase within the average size range 10 to 200 μm by agitationin the presence of an emulsion stabilizer and solidifying saidparticles; and recovering, washing and drying said particles to obtainsaid procatalyst.

EP 0 019 330 of Dow discloses a Ziegler-Natta type catalyst composition.Said olefin polymerization catalyst composition is prepared using aprocess comprising: a) a reaction product of an organo aluminum compoundand an electron donor, and b) a solid component which has been obtainedby halogenating a magnesium compound with the formula MgR¹R² wherein R¹is an alkyl, aryl, alkoxide or aryloxide group and R² is an alkyl, aryl,alkoxide or aryloxide group or halogen, are contacted with a halide oftetravalent titanium in the presence of a halohydrocarbon, andcontacting the halogenated product with a tetravalent titanium compound.This production method as disclosed in EP 0 019 330 is incorporated byreference.

The Examples of U.S. Pat. No. 5,093,415 of Dow discloses an improvedprocess to prepare a procatalyst. Said process includes a reactionbetween titanium tetrachloride, diisobutyl phthalate, and magnesiumdiethoxide to obtain a solid material. This solid material is thenslurried with titanium tetrachloride in a solvent and phthaloyl chlorideis added. The reaction mixture is heated to obtain a solid materialwhich is reslurried in a solvent with titanium tetrachloride. Again thiswas heated and a solid collected. Once again the solid was reslurriedonce again in a solution of titanium tetrachloride to obtain a catalyst.The Examples of U.S. Pat. No. 5,093,415 are incorporated by reference.

Example 2 of U.S. Pat. No. 6,825,146,2 of Dow discloses another improvedprocess to prepare a catalyst. Said process includes a reaction betweentitanium tetrachloride in solution with a precursor composition—preparedby reacting magnesium diethoxide, titanium tetraethoxide, and titaniumtetrachloride, in a mixture of ortho-cresol, ethanol andchlorobenzene—and ethylbenzoate as electron donor. The mixture washeated and a solid was recovered. To the solid titanium tetrachloride, asolvent and benzoylchloride were added. The mixture was heated to obtaina solid product. The last step was repeated. The resulting solidprocatalyst was worked up to provide a catalyst. Example 2 of U.S. Pat.No. 6,825,146,2 is incorporated by reference.

U.S. Pat. No. 4,771,024 discloses the preparation of a catalyst oncolumn 10, line 61 to column 11, line 9. The section “catalystmanufacture on silica” is incorporated into the present application byreference. The process comprises combining dried silica with carbonatedmagnesium solution (magnesium diethoxide in ethanol was bubbled withCO₂). The solvent was evaporated at 85° C. The resulting solid waswashed and a 50:50 mixture of titanium tetrachloride and chlorobenzenewas added to the solvent together with ethylbenzoate. The mixture washeated to 100° C. and liquid filtered. Again TiCl₄ and chlorobenzenewere added, followed by heating and filtration. A final addition ofTiCl₄ and chlorobenzene and benzoylchloride was carried out, followed byheating and filtration. After washing the catalyst was obtained.

WO03/068828 discloses a process for preparing a catalyst component onpage 91 “preparation of solid catalyst components” which section isincorporated into the present application by reference. Magnesiumchloride, toluene, epoxy chloropropane and tributyl phosphate were addedunder nitrogen to a reactor, followed by heating. Then phthalicanhydride was added. The solution was cooled to −25° C. and TiCl₄ wasadded drop wise, followed by heating. An internal donor was added(1,3-diphenyl-1,3-propylene glycol dibenzoate,2-methyl-1,3-diphenyl-1,3-propylene glycol dibenzoate,1,3-diphenyl-1,3-propylene-glycol diproprionate, or1,3-diphenyl-2-methyl-1,3-propylene glycol diproprionate) and afterstirring a solid was obtained and washed. The solid was treated withTiCl₄ in toluene twice, followed by washing to obtain a catalystcomponent.

U.S. Pat. No. 4,866,022 discloses a catalyst component comprises aproduct formed by: A. forming a solution of a magnesium-containingspecies from a magnesium carbonate or a magnesium carboxylate; B.precipitating solid particles from such magnesium-containing solution bytreatment with a transition metal halide and an organosilane having aformula: R_(n)SiR′_(4-n), wherein n=0 to 4 and wherein R is hydrogen oran alkyl, a haloalkyl or aryl radical containing one to about ten carbonatoms or a halosilyl radical or haloalkylsilyl radical containing one toabout eight carbon atoms, and R′ is OR or a halogen: C. reprecipitatingsuch solid particles from a mixture containing a cyclic ether; and D.treating the reprecipitated particles with a transition metal compoundand an electron donor. This process for preparing a catalyst isincorporated into the present application by reference.

The procatalyst used in the catalyst system according to the presentinvention may be produced by any method known in the art.

The procatalyst may also be produced as disclosed in WO96/32426A; thisdocument discloses a process for the polymerization of propylene using acatalyst comprising a catalyst component obtained by a process wherein acompound with formula Mg(OAlk)_(x)Cl_(y) wherein x is larger than 0 andsmaller than 2, y equals 2-x and each Alk, independently, represents analkyl group, is contacted with a titanium tetraalkoxide and/or analcohol in the presence of an inert dispersant to give an intermediatereaction product and wherein the intermediate reaction product iscontacted with titanium tetrachloride in the presence of an internaldonor, which is di-n-butyl phthalate (DBP).

Preferably, the Ziegler-Natta type procatalyst in the catalyst systemaccording to the present invention is obtained by the process asdescribed in WO 2007/134851 A1. In Example I the process is disclosed inmore detail. Example I including all sub-examples (IA-IE) of WO2007/134851 A1 is incorporated into the present description. Moredetails about the different embodiments are disclosed starting on page3, line 29 to page 14 line 29 of WO 2007/134851 A1. These embodimentsare incorporated by reference into the present description. This processproduces the TiNo procatalyst discussed above.

In the following part of the description the different steps and phasesof the process for preparing the procatalyst for use in a catalystsystem according to an embodiment of the present invention will bediscussed.

The process for preparing a procatalyst for use in a catalyst systemaccording to an embodiment of the present invention comprises thefollowing phases:

-   -   Phase A): preparing a solid support for the procatalyst;    -   Phase B): optionally activating said solid support obtained in        phase A) using one or more activating compounds to obtain an        activated solid support;    -   Phase C): contacting said solid support obtained in phase A) or        said activated solid support in phase B) with a catalytic        species wherein phase C) comprises one of the following:        -   contacting said solid support obtained in phase A) or said            activated solid support in phase B) with a catalytic species            to obtain said procatalyst; or        -   contacting said solid support obtained in phase A) or said            activated solid support in phase B) with a catalytic species            and one or more internal donors to obtain said procatalyst;            or        -   contacting said solid support obtained in phase A) or said            activated solid support in phase B) with a catalytic species            and one or more internal donors to obtain an intermediate            product; or        -   iv) contacting said solid support obtained in phase A) or            said activated solid support in phase B) with a catalytic            species and an activator to obtain an intermediate product;    -   optionally Phase D: modifying said intermediate product obtained        in phase C) wherein phase D) comprises on of the following:        -   modifying said intermediate product obtained in phase C)            with a Group 13- or transition metal modifier in case an            internal donor was used during phase C), in order to obtain            a procatalyst;        -   modifying said intermediate product obtained in phase C)            with a Group 13- or transition metal modifier and one or            more internal donors in case an activator was used during            phase C), in order to obtain a procatalyst.

The procatalyst thus prepared can be used to prepare a catalyst systemthat can be used in polymerization of olefins combined with an externaldonor and a co-catalyst.

The various steps used to prepare the procatalyst for use in a catalystsystem according to an embodiment of the present invention are describedin more detail below.

Phase A: Preparing a Solid Support for the Procatalyst

In the process for preparing a procatalyst for use in a catalyst systemaccording to an embodiment of the present invention preferably amagnesium-containing support is used. Said magnesium-containing supportis known in the art as a typical component of a Ziegler-Nattaprocatalyst. The following description explains the process of preparingmagnesium-based support. Other supports may be used.

Synthesis of magnesium-containing supports, such as magnesium halides,magnesium alkyls and magnesium aryls, and also magnesium alkoxy andmagnesium aryloxy compounds for polyolefin production, particularly ofpolypropylenes production are described for instance in U.S. Pat. No.4,978,648, WO96/32427A1, WO01/23441 A1, EP1283 222A1, EP1222 214B1; U.S.Pat. No. 5,077,357; U.S. Pat. No. 5,556,820; U.S. Pat. No. 4,414,132;U.S. Pat. No. 5,106,806 and U.S. Pat. No. 5,077,357 but the presentprocess is not limited to the disclosure in these documents.

Preferably, the process for preparing the solid support for theprocatalyst for use in a catalyst system according to an embodiment ofthe present invention comprises the following steps: step o) which isoptional and step i).

Step o) Preparation of the Grignard Reagent (Optional)

A Grignard reagent, R⁴ _(z)MgX⁴ _(2-z) used in step i) may be preparedby contacting metallic magnesium with an organic halide R⁴X⁴, asdescribed in WO 96/32427 A1 and WO01/23441 A1. All forms of metallicmagnesium may be used, but preferably use is made of finely dividedmetallic magnesium, for example magnesium powder. To obtain a fastreaction it is preferable to heat the magnesium under nitrogen prior touse.

R⁴ is a hydrocarbyl group independently selected from alkyl, alkenyl,aryl, aralkyl, alkylaryl, or alkoxycarbonyl groups, wherein saidhydrocarbyl group may be linear, branched or cyclic, and may besubstituted or unsubstituted; said hydrocarbyl group preferably havingbetween 1 and 20 carbon atoms or combinations thereof. The R⁴ group maycontain one or more heteroatoms.

X⁴ is selected from the group of consisting of fluoride (F—), chloride(Cl—), bromide (Br—) or iodide (I—).

The value for z is in a range of larger than 0 and smaller than 2: 0<z<2Combinations of two or more organic halides R⁴X⁴ can also be used.

The magnesium and the organic halide R⁴X⁴ can be reacted with each otherwithout the use of a separate dispersant; the organic halide R⁴X⁴ isthen used in excess.

The organic halide R⁴X⁴ and the magnesium can also be brought intocontact with one another and an inert dispersant. Examples of thesedispersants are: aliphatic, alicyclic or aromatic dispersants containingfrom 4 up to 20 carbon atoms.

Preferably, in this step o) of preparing R⁴ _(z)MgX⁴ _(2-z), also anether is added to the reaction mixture. Examples of ethers are: diethylether, diisopropyl ether, dibutyl ether, diisobutyl ether, diisoamylether, diallyl ether, tetrahydrofuran and anisole. Dibutyl ether and/ordiisoamyl ether are preferably used. Preferably, an excess ofchlorobenzene is used as the organic halide R⁴X⁴. Thus, thechlorobenzene serves as dispersant as well as organic halide R⁴X⁴.

The organic halide/ether ratio acts upon the activity of theprocatalyst. The chlorobenzene/dibutyl ether volume ratio may forexample vary between 75:25 and 35:65, preferably between 70:30 and50:50.

Small amounts of iodine and/or alkyl halides can be added to cause thereaction between the metallic magnesium and the organic halide R⁴X⁴ toproceed at a higher rate. Examples of alkyl halides are butyl chloride,butyl bromide and 1,2-dibromoethane. When the organic halide R⁴X⁴ is analkyl halide, iodine and 1,2-dibromoethane are preferably used.

The reaction temperature for step o) of preparing R⁴ _(z)MgX⁴ _(2-z)normally is between 20 and 150° C.; the reaction time is normallybetween 0.5 and 20 hours. After the reaction for preparing R⁴ _(z)MgX⁴_(2-z) is completed, the dissolved reaction product may be separatedfrom the solid residual products. The reaction may be mixed. Thestirring speed can be determined by a person skilled in the art andshould be sufficient to agitate the reactants.

Step i) reacting a Grignard compound with a silane compound Step i):contacting a compound R⁴ _(z)MgX⁴ _(2-z)—wherein R₄, X⁴, and z are asdiscussed above—with an alkoxy- or aryloxy-containing silane compound togive a first intermediate reaction product. Said first intermediatereaction product is a solid magnesium-containing support. It should benoted that with “alkoxy- or aryloxy-containing” is meant OR¹ containing.In other words said alkoxy- or aryloxy-containing silane compoundcomprises at least one OR¹ group. R¹ is selected from the groupconsisting of a linear, branched or cyclic hydrocarbyl groupindependently selected e.g. from alkyl, alkenyl, aryl, aralkyl,alkoxycarbonyl or alkylaryl groups, and one or more combinationsthereof; wherein said hydrocarbyl group may be substituted orunsubstituted, may contain one or more heteroatoms and preferably hasfrom 1 to 20 carbon atoms.

In step i) a first intermediate reaction product is thus prepared bycontacting the following reactants: * a Grignard reagent—being acompound or a mixture of compounds of formula R⁴ _(z)MgX⁴ _(2-z) and *an alkoxy- or aryloxy-containing silane compound. Examples of thesereactants are disclosed for example in WO 96/32427 A1 and WO01/23441 A1.

The compound R⁴ _(z)MgX⁴ _(2-z) used as starting product is alsoreferred to as a Grignard compound. In R⁴ _(z)MgX⁴ _(2-z), X⁴ ispreferably chloride or bromide, more preferably chloride.

R⁴ can be an alkyl, aryl, aralkyl, alkoxide, phenoxide, etc., ormixtures thereof. Suitable examples of group R⁴ are methyl, ethyl,n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, hexyl, cyclohexyl, octyl,phenyl, tolyl, xylyl, mesityl, benzyl, phenyl, naphthyl, thienyl,indolyl. In a preferred embodiment of the invention, R⁴ represents anaromatic group, for instance a phenyl group.

Preferably, as Grignard compound R⁴ _(z)MgX⁴ _(2-z) used in step i) aphenyl Grignard or a butyl Grignard is used. The selection for eitherthe phenyl Grignard or the butyl Grignard depends on the requirements.

When a Grignard compound is used, a compound according to the formula R⁴_(z)MgX⁴ _(2-z) is meant. When phenyl Grignard is used a compoundaccording to the formula R⁴ _(z)MgX⁴ _(2-z) wherein R⁴ is phenyl, e.g.PhMgCl, is meant. When butyl Grignard is used, a compound according tothe formula R⁴ _(z)MgX⁴ _(2-z) wherein R⁴ is butyl, e.g. BuMgCl orn-BuMgCl, is meant.

An advantage of the use of phenyl Grignard are that it is more activethat butyl Grignard. Preferably, when butyl Grignard is used, anactivation step using an aliphatic alcohol, such as methanol is carriedout in order to increase the activity. Such an activation step may notbe required with the use of phenyl Grignard. A disadvantage of the useof phenyl Grignard is that benzene rest products may be present and thatit is more expensive and hence commercially less interesting.

An advantage of the use of butyl Grignard is that it is benzene free andis commercially more interesting due to the lower price. A disadvantageof the use of butyl Grignard is that in order to have a high activity,an activation step is required.

The process to prepare the procatalyst for use in an embodiment of thepresent invention can be carried out using any Grignard compound, butthe two stated above are the two that are most preferred.

In the Grignard compound of formula R⁴ _(z)MgX⁴ _(2-z) is preferablyfrom about 0.5 to 1.5.

The compound R⁴ _(z)MgX⁴ _(2-z) may be prepared in an optional step(step o)) which is discussed above), preceding step i) or may beobtained from a different process.

It is explicitly noted that it is possible that the Grignard compoundused in step i) may alternatively have a different structure, forexample, may be a complex. Such complexes are already known to theskilled person in the art; a particular example of such complexes isphenyl₄Mg₃Cl₂.

The alkoxy- or aryloxy-containing silane used in step i) is preferably acompound or a mixture of compounds with the general formulaSi(OR⁵)_(4-n)R⁶ _(n),

Wherein it should be noted that the R⁵ group is the same as the R¹group. The R¹ group originates from the R⁵ group during the synthesis ofthe first intermediate reaction product.

R⁵ is a hydrocarbyl group independently selected e.g. from alkyl,alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one ormore combinations thereof. Said hydrocarbyl group may be linear,branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 20carbon atoms, more preferably between 1-12 carbon atoms, even morepreferably between 1 and 6 carbon atoms. Preferably, said hydrocarbylgroup is an alkyl group, preferably having between 1 and 20 carbonatoms, more preferably between 1-12 carbon atoms, even more preferablybetween 1 and 6 carbon atoms, such as for example methyl, ethyl,n-propyl, isopropyl, n-butyl, sec-butyl, iso-butyl, t-butyl, pentyl orhexyl; most preferably, selected from ethyl and methyl.

R⁶ is a hydrocarbyl group independently selected e.g. from alkyl,alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one ormore combinations thereof. Said hydrocarbyl group may be linear,branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 20carbon atoms, more preferably between 1-12 carbon atoms, even morepreferably between 1 and 6 carbon atoms. Preferably, said hydrocarbylgroup is an alkyl group, preferably having between 1 and 20 carbonatoms, more preferably between 1-12 carbon atoms, even more preferablybetween 1 and 6 carbon atoms, such as for example methyl, ethyl,n-propyl, isopropyl, n-butyl, sec-butyl, iso-butyl, t-butyl orcyclopentyl.

The value for n is in the range of 0 up to 4, preferably n is from 0 upto and including 1.

Examples of suitable silane-compounds include tetramethoxysilane,tetraethoxysilane, methyltrimethoxysilane, methyltributoxysilane,phenyltriethoxy-silane, diethyldiphenoxysilane, n-propyltriethoxysilane,diisopropyldi-methoxysilane, diisobutyldimethoxysilane,n-propyltrimethoxysilane, cyclohexyl-methyldimethoxysilane,dicyclopentyldimethoxy-silane, isobutylisopropyldimethoxyl-silane,phenyl-trimethoxysilane, diphenyl-dimethoxysilane,trifluoropropylmethyl-dimethoxysilane,bis(perhydroisoquinolino)-dimethoxysilane, dicyclohexyldimethoxy-silane,dinorbornyl-dimethoxysilane, di(n-propyl)dimethoxysilane,di(iso-propyl)-dimethoxysilane, di(n-butyl)dimethoxysilane and/ordi(iso-butyl)dimethoxysilane.

Preferably, tetraethoxy-silane is used as silane-compound in preparingthe solid Mg-containing compound during step i) in the process accordingto the present invention.

Preferably, in step i) the silane-compound and the Grignard compound areintroduced simultaneously to a mixing device to result in particles ofthe first intermediate reaction product having advantageous morphology.This is for example described in WO 01/23441 Al. Here, ‘morphology’ doesnot only refer to the shape of the particles of the solid Mg-compoundand the catalyst made therefrom, but also to the particle sizedistribution (also characterized as span, viz. an indicator for thewidth of the particle size distribution as measured according to ISO13320:2009), its fines content, powder flowability, and the bulk density(viz. the weight per unit volume of a material, including voids inherentin the material as tested; measured as apparent density according toASTM D1895-96 Reapproved 2010-e1, test method A) of the catalystparticles. Moreover, it is well known that a polyolefin powder producedin polymerization process using a catalyst system based on suchprocatalyst has a similar morphology as the procatalyst (the so-called“replica effect”; see for instance S. van der Ven, Polypropylene andother Polyolefins, Elsevier 1990, p. 8-10). Accordingly, almost roundpolymer particles are obtained with a length/diameter ratio (I/D)smaller than 2 and with good powder flowability.

As discussed above, the reactants are preferably introducedsimultaneously. With “introduced simultaneously” is meant that theintroduction of the Grignard compound and the silane-compound is done insuch way that the molar ratio Mg/Si does not substantially vary duringthe introduction of these compounds to the mixing device, as describedin WO 01/23441 A1.

The silane-compound and Grignard compound can be continuously orbatch-wise introduced to the mixing device. Preferably, both compoundsare introduced continuously to a mixing device.

The mixing device can have various forms; it can be a mixing device inwhich the silane-compound is premixed with the Grignard compound, themixing device can also be a stirred reactor, in which the reactionbetween the compounds takes place. The separate components may be dosedto the mixing device by means of peristaltic pumps.

Preferably, the compounds are premixed before the mixture is introducedto the reactor for step i). In this way, a procatalyst is formed with amorphology that leads to polymer particles with the best morphology(high bulk density, narrow particle size distribution, (virtually) nofines, excellent flowability).

The Si/Mg molar ratio during step i) may range from 0.2 to 20.Preferably, the Si/Mg molar ratio is from 0.4 to 1.0.

The period of premixing of the reactants in above indicated reactionstep may vary between wide limits, for instance 0.1 to 300 seconds.Preferably, premixing is performed during 1 to 50 seconds.

The temperature during the premixing step of the reactants is notspecifically critical, and may for instance range between 0 and 80° C.;preferably the temperature is between 10° C. and 50° C.

The reaction between said reactants may, for instance, take place at atemperature between −20° C. and 100° C.; for example at a temperature offrom 0° C. to 80° C. The reaction time is for example between 1 and 5hours.

The mixing speed during the reaction depends on the type of reactor usedand the scale of the reactor used. The mixing speed can be determined bya person skilled in the art. As a non-limiting example, mixing may becarried out at a mixing speed of between 250-300 rpm. In an embodiment,when a blade stirrer is used the mixing speed is between 220 and 280 rpmand when a propeller stirrer is used the mixing speed is between 270 and330 rpm. The stirrer speed may be increased during the reaction. Forexample, during the dosing, the speed of stirring may be increased everyhour by 20-30 rpm.

The first intermediate reaction product obtained from the reactionbetween the silane compound and the Grignard compound is usuallypurified by decanting or filtration followed by rinsing with an inertsolvent, for instance a hydrocarbon solvent with for example 1-20 carbonatoms, like pentane, iso-pentane, hexane or heptane. The solid productcan be stored and further used as a suspension in said inert solvent.Alternatively, the product may be dried, preferably partly dried, andpreferably under mild conditions; e.g. at ambient temperature andpressure.

The first intermediate reaction product obtained by this step i) maycomprise a compound of the formula Mg(OR¹)_(x)X¹ _(2-x), wherein:

R¹ is a hydrocarbyl group independently selected e.g. from alkyl,alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one ormore combinations thereof. Said hydrocarbyl group may be linear,branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 20carbon atoms, more preferably between 1-12 carbon atoms, even morepreferably between 1 and 6 carbon atoms. Preferably, said hydrocarbylgroup is an alkyl group, preferably having between 1 and 20 carbonatoms, more preferably between 1-12 carbon atoms, even more preferablybetween 1 and 6 carbon atoms. Most preferably selected from ethyl andmethyl.

X¹ is selected from the group of consisting of fluoride (F—), chloride(Cl—), bromide (Br—) or iodide (I—). Preferably, X¹ is chloride orbromine and more preferably, X¹ is chloride. The value for x is in therange of larger than 0 and smaller than 2: 0<z<2. The value for x ispreferably between 0.5 and 1.5.

Phase B: Activating Said Solid Support for the Catalyst

This step of activating said solid support for the procatalyst is anoptional step that is not required, but is preferred, in the presentinvention. If this step of activation is carried out, preferably, theprocess for activating said solid support comprises the following stepii). This phase may comprise one or more stages.

Step ii) Activation of the Solid Magnesium Compound

Step ii): contacting the solid Mg(OR′)_(x)X′¹ _(2-x) with at least oneactivating compound selected from the group formed by activatingelectron donors and metal alkoxide compounds of formulaM¹(OR²)_(v-w)(OR³)_(w) or M²(OR²)_(v-w)(R³)_(w), wherein:

R² is a hydrocarbyl group independently selected e.g. from alkyl,alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one ormore combinations thereof. Said hydrocarbyl group may be linear,branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 20carbon atoms, more preferably between 1-12 carbon atoms, even morepreferably between 1 and 6 carbon atoms. Preferably, said hydrocarbylgroup is an alkyl group, preferably having between 1 and 20 carbonatoms, more preferably between 1-12 carbon atoms, even more preferablybetween 1 and 6 carbon atoms, such as for example methyl, ethyl,n-propyl, isopropyl, n-butyl, sec-butyl, iso-butyl, t-butyl, pentyl orhexyl; most preferably selected from ethyl and methyl.

R³ is a hydrocarbyl group independently selected e.g. from alkyl,alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one ormore combinations thereof. Said hydrocarbyl group may be linear,branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 20carbon atoms, more preferably between 1-12 carbon atoms, even morepreferably between 1 and 6 carbon atoms. Preferably, said hydrocarbylgroup is an alkyl group, preferably having between 1 and 20 carbonatoms, more preferably between 1-12 carbon atoms, even more preferablybetween 1 and 6 carbon atoms; most preferably selected from methyl,ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, iso-butyl, t-butyl, andcyclopentyl.

M¹ is a metal selected from the group consisting of Ti, Zr, Hf, Al orSi; v is the valency of M¹;

M² is a metal being Si; v is the valency of M² and w is smaller than v.

The electron donors and the compounds of formula M(OR²)_(v-w)(OR³)_(w)and M(OR²)_(v-w)(R³)_(w) may be also referred herein as activatingcompounds.

In this step either one or both types of activating compounds (viz.activating electron donor or metal alkoxides) may be used.

The advantage of the use of this activation step prior to contacting thesolid support with the halogen-containing titanium compound (processphase C) is that a higher yield of polyolefins is obtained per gram ofthe procatalyst. Moreover, the ethylene sensitivity of the catalystsystem in the copolymerization of propylene and ethylene is alsoincreased because of this activation step. This activation step isdisclosed in detail in WO2007/134851 of the present applicant.

Examples of suitable activating electron donors that may be used in stepii) are known to the skilled person and described herein below, i.e.include carboxylic acids, carboxylic acid anhydrides, carboxylic acidesters, carboxylic acid halides, alcohols, ethers, ketones, amines,amides, nitriles, aldehydes, alkoxides, sulfonamides, thioethers,thioesters and other organic compounds containing one or more heteroatoms, such as nitrogen, oxygen, sulfur and/or phosphorus.

Preferably, an alcohol is used as the activating electron donor in stepii). More preferably, the alcohol is a linear or branched aliphatic oraromatic alcohol having 1-12 carbon atoms. Even more preferably, thealcohol is selected from methanol, ethanol, butanol, isobutanol,hexanol, xylenol and benzyl alcohol. Most preferably, the alcohol isethanol or methanol, preferably ethanol.

Suitable carboxylic acids as activating electron donor may be aliphaticor (partly) aromatic. Examples include formic acid, acetic acid,propionic acid, butyric acid, isobutanoic acid, acrylic acid,methacrylic acid, maleic acid, fumaric acid, tartaric acid,cyclohexanoic monocarboxylic acid, cis-1,2-cyclohexanoic dicarboxylicacid, phenyl-carboxylic acid, toluene-carboxylic acid,naphthalene-carboxylic acid, phthalic acid, isophthalic acid,terephthalic acid and/or trimellitic acid.

Anhydrides of the aforementioned carboxylic acids can be mentioned asexamples of carboxylic acid anhydrides, such as for example acetic acidanhydride, butyric acid anhydride and methacrylic acid anhydride.

Suitable examples of esters of above-mentioned carboxylic acids areformates, for instance, butyl formate; acetates, for instance ethylacetate and butyl acetate; acrylates, for instance ethyl acrylate,methyl methacrylate and isobutyl methacrylate; benzoates, for instancemethylbenzoate and ethylbenzoate; methyl-p-toluate; ethyl-naphthate andphthalates, for instance monomethyl phthalate, dibutyl phthalate,diisobutyl phthalate, diallyl phthalate and/or diphenyl phthalate.

Examples of suitable carboxylic acid halides as activating electrondonors are the halides of the carboxylic acids mentioned above, forinstance acetyl chloride, acetyl bromide, propionyl chloride, butanoylchloride, butanoyl iodide, benzoyl bromide, p-toluyl chloride and/orphthaloyl dichloride.

Suitable alcohols are linear or branched aliphatic alcohols with 1-12C-atoms, or aromatic alcohols. Examples include methanol, ethanol,butanol, isobutanol, hexanol, xylenol and benzyl alcohol. The alcoholsmay be used alone or in combination. Preferably, the alcohol is ethanolor hexanol.

Examples of suitable ethers are diethers, such as2-ethyl-2-butyl-1,3-dimethoxypropane,2-isopropyl-2-isopentyl-1,3-dimethoxypropane and/or9,9-bis(methoxymethyl) fluorene. Also, cyclic ethers liketetrahydrofuran (THF), or tri-ethers can be used.

Suitable examples of other organic compounds containing a heteroatom foruse as activating electron donor include 2,2,6,6-tetramethyl piperidine,2,6-dimethylpiperidine, pyridine, 2-methylpyridine, 4-methylpyridine,imidazole, benzonitrile, aniline, diethylamine, dibutylamine,dimethylacetamide, thiophenol, 2-methyl thiophene, isopropyl mercaptan,diethylthioether, diphenylthioether, tetrahydrofuran, dioxane,dimethylether, diethylether, anisole, acetone, triphenylphosphine,triphenylphosphite, diethylphosphate and/or diphenylphosphate.

Examples of suitable metal alkoxides for use in step ii) are metalalkoxides of formulas: M¹(OR²)_(v-w)(OR³)_(w) and M²(OR²)_(v-w)(R³)_(w)wherein M¹, M², R², R³, v, and w are as defined herein. R² and R³ canalso be aromatic hydrocarbon groups, optionally substituted with e.g.alkyl groups and can contain for example from 6 to 20 carbon atoms. TheR² and R³ preferably comprise 1-12 or 1-8 carbon atoms. In preferredembodiments R² and R³ are ethyl, propyl or butyl; more preferably allgroups are ethyl groups.

Preferably, M¹ in said activating compound is Ti or Si. Si-containingcompounds suitable as activating compounds are the same as listed abovefor step i).

The value of w is preferably 0, the activating compound being forexample a titanium tetraalkoxide containing 4-32 carbon atoms in totalfrom four alkoxy groups. The four alkoxide groups in the compound may bethe same or may differ independently. Preferably, at least one of thealkoxy groups in the compound is an ethoxy group. More preferably thecompound is a tetraalkoxide, such as titanium tetraethoxide.

In the preferred process to prepare the procatalyst, one activatingcompound can be used, but also a mixture of two or more compounds may beused.

A combination of a compound of M¹(OR²)_(v-w)(OR³)_(w) orM²(OR²)_(v-w)(R³)_(w) with an electron donor is preferred as activatingcompound to obtain a catalyst system that for example shows highactivity, and of which the ethylene sensitivity can be affected byselecting the internal donor; which is specifically advantageous inpreparing copolymers of for example propylene and ethylene.

Preferably, a Ti-based compound, for example titanium tetraethoxide, isused together with an alcohol, like ethanol or hexanol, or with an estercompound, like ethylacetate (EA), ethylbenzoate (EB) or a phthalateester, or together with an ether, like dibutylether (DBE), or withpyridine.

If two or more activating compounds are used in step ii) their order ofaddition is not critical, but may affect catalyst performance dependingon the compounds used. A skilled person may optimize their order ofaddition based on some experiments. The compounds of step ii) can beadded together or sequentially.

Preferably, an electron donor compound is first added to the compoundwith formula Mg(OR¹)_(x)X¹ _(2-x) where after a compound of formulaM¹(OR²)_(v-w)(OR³)_(w) or M²(OR²)_(v-w)(R³)_(w) as defined herein isadded. The activating compounds preferably are added slowly, forinstance during a period of 0.1-6, preferably during 0.5-4 hours, mostpreferably during 1-2.5 hours, each.

The first intermediate reaction product that is obtained in step i) canbe contacted—when more than one activating compound is used—in anysequence with the activating compounds. In one embodiment, an activatingelectron donor is first added to the first intermediate reaction productand then the compound M¹(OR²)_(v-w)(OR³)_(w) Or M²(OR²)_(v-w)(R³)_(w) isadded; in this order no agglomeration of solid particles is observed.The compounds in step ii) are preferably added slowly, for instanceduring a period of 0.1-6, preferably during 0.5-4 hours, most preferablyduring 1-2.5 hours, each.

The molar ratio of the activating compound to Mg(OR¹)_(x)X′¹ _(2-x) mayrange between wide limits and is, for instance, between 0.02 and 1.0.Preferably the molar ratio is between 0.05 and 0.5, more preferablybetween 0.06 and 0.4, or even between 0.07 and 0.2.

The temperature in step ii) can be in the range from −20° C. to 70° C.,preferably from −10° C. to 50° C., more preferably in the range from −5°C. to 40° C., and most preferably in the range between 0° C. and 30° C.

Preferably, at least one of the reaction components is dosed in time,for instance during 0.1 to 6, preferably during 0.5 to 4 hours, moreparticularly during 1 to 2.5 hours.

The reaction time after the activating compounds have been added ispreferably between 0 and 3 hours.

The mixing speed during the reaction depends on the type of reactor usedand the scale of the reactor used. The mixing speed can be determined bya person skilled in the art and should be sufficient to agitate thereactants.

The inert dispersant used in step ii) is preferably a hydrocarbonsolvent. The dispersant may be for example an aliphatic or aromatichydrocarbon with 1-20 carbon atoms. Preferably, the dispersant is analiphatic hydrocarbon, more preferably pentane, iso-pentane, hexane orheptane, heptane being most preferred.

Starting from a solid Mg-containing product of controlled morphologyobtained in step i), said morphology is not negatively affected duringtreatment with the activating compound during step ii). The solid secondintermediate reaction product obtained in step ii) is considered to bean adduct of the Mg-containing compound and the at least one activatingcompound as defined in step ii), and is still of controlled morphology.

The obtained second intermediate reaction product after step ii) may bea solid and may be further washed, preferably with the solvent also usedas inert dispersant; and then stored and further used as a suspension insaid inert solvent. Alternatively, the product may be dried, preferablypartly dried, preferably slowly and under mild conditions; e.g. atambient temperature and pressure.

Phase C: Contacting Said Solid Support with the Catalytic Species andOptionally One or More Internal Donors and/or an Activator.

Phase C: contacting the solid support with a catalytic species. Thisstep can take different forms, such as i) contacting said solid supportwith a catalytic species to obtain said procatalyst; ii) contacting saidsolid support with the catalytic species and one or more internal donorsto obtain said procatalyst; iii) contacting said solid support with acatalytic species and one or more internal donors to obtain anintermediate product; iv) contacting said solid support with a catalyticspecies and an activator donor to obtain an intermediate product.

The contacting of the solid support with the catalytic species maycomprise several stages (e.g. I, II and/or III). During each of theseconsecutive stages the solid support is contacted with said catalyticspecies. In other words, the addition or reaction of said catalyticspecies may be repeated one or more times. The same or differentcatalytic species may be used during these stages.

These stages may be divided over Phase C (e.g. step iii) and Phase D(e.g. step v) or step v-a) and v-b). It is possible that Phase Ccomprises one or more stages and that Phase D comprises also one or morestages.

For example, during stage I in phase C (step iii) the solid support(first intermediate) or the activated solid support (secondintermediate) is first contacted with said catalytic species andoptionally subsequently with one or more internal donors and optionallyan activator. When a second stage is present, during stage II (eitherPhase C or Phase D) the intermediate product obtained from stage I willbe contacted with additional catalytic species which may the same ordifferent than the catalytic species added during the first stage andoptionally one or more internal donors and optionally an activator.

In case three stages are present, in an embodiment, stage III is v) ofPhase D which is preferably a repetition of stage I or may comprise thecontacting of the product obtained from phase II with both a catalyticspecies (which may be the same or different as above) and one or moreinternal donors. In other words, an internal donor may be added duringeach of these stages or during two or more of these stages. When aninternal donor is added during more than one stage it may be the same ora different internal donor. In an embodiment stage I is step iii) ofPhase C, stage II is step va) of Phase D, and stage III is step vb) ofPhase D.

An activator according to the present invention—if used—may be addedeither during stage I or stage II or stage III. An activator may also beadded during more than one stage.

Preferably, the process of contacting the solid support with thecatalytic species and an internal donor comprises the following stepiii).

Step iii) Reacting the Solid Support with a Transition Metal Halide

Step iii) reacting the solid support with a transition metal halide(e.g. halide of titanium, chromium, hafnium, zirconium or vanadium) butpreferably titanium halide. In the discussion below only the process fora titanium-base Ziegler-Natta procatalyst is disclosed, however, thepresent invention is also applicable to other types of Ziegler-Nattaprocatalysts.

Step iii): contacting the first or second intermediate reaction product,obtained respectively in step i) or ii), with a halogen-containingTi-compound and optionally an internal electron donor or activator toobtain a third intermediate product.

Step iii) can be carried out after step i) on the first intermediateproduct or after step ii) on the second intermediate product.

The molar ratio in step iii) of the transition metal to the magnesiumpreferably is between 10 and 100, most preferably, between 10 and 50.

Preferably, an internal electron donor is also present during step iii).Also mixtures of internal electron donors can be used. Examples ofinternal electron donors are disclosed below.

The molar ratio of the internal electron donor relative to the magnesiummay vary between wide limits, for instance between 0.02 and 0.75.Preferably, this molar ratio is between 0.05 and 0.4; more preferablybetween 0.1 and 0.4; and most preferably between 0.1 and 0.3.

During contacting the first or second intermediate product and thehalogen-containing titanium compound, an inert dispersant is preferablyused. The dispersant preferably is chosen such that virtually all sideproducts formed are dissolved in the dispersant. Suitable dispersantsinclude for example aliphatic and aromatic hydrocarbons and halogenatedaromatic solvents with for instance 4-20 carbon atoms. Examples includetoluene, xylene, benzene, heptane, o-chlorotoluene and chlorobenzene.

The reaction temperature during step iii) is preferably between 0° C.and 150° C., more preferably between 50° C. and 150° C., and morepreferably between 100° C. and 140° C. Most preferably, the reactiontemperature is between 110° C. and 125° C.

The reaction time during step iii) is preferably between 10 minutes and10 hours. In case several stages are present, each stage can have areaction time between 10 minutes and 10 hours. The reaction time can bedetermined by a person skilled in the art based on the type and scale ofthe reactor and the catalyst systems.

The mixing speed during the reaction depends on the type and the scaleof the reactor used. The mixing speed can be determined by a personskilled in the art and should be sufficient to agitate the reactants.

The obtained reaction product may be washed, usually with an inertaliphatic or aromatic hydrocarbon or halogenated aromatic compound, toobtain the procatalyst of the invention. If desired the reaction andsubsequent purification steps may be repeated one or more times. A finalwashing is preferably performed with an aliphatic hydrocarbon to resultin a suspended or at least partly dried procatalyst, as described abovefor the other steps.

Optionally an activator is present during step iii) of Phase C insteadof an internal donor, this is explained in more detail below in thesection of activators.

The molar ratio of the activator relative to the magnesium may varybetween wide limits, for instance between 0.02 and 0.5. Preferably, thismolar ratio is between 0.05 and 0.4; more preferably between 0.1 and0.3; and most preferably between 0.1 and 0.2.

Phase D: Modifying Said Procatalyst with a Metal-Based Modifier.

This phase D is optional in the present invention. In a preferredprocess for modifying the supported procatalyst, this phase comprisesthe following steps: Step iv) modifying the third intermediate productwith a metal-modifier to yield a modified intermediate product

After step iv)—if this is carried out—an additional step of contactingthe intermediate product with a catalytic species (in other words, anadditional stage):

Step v) contacting said modified intermediate product with a titaniumhalide and optionally on or more internal donors and/or activators toobtain the present procatalyst. In case no activator is used duringPhase C, an activator is used during step v) of Phase D.

The order of addition, viz. the order of first step iv) and subsequentlystep v) is considered to be very important to the formation of thecorrect clusters of Group 13- or transition metal and titanium formingthe modified and more active catalytic center.

Each of these steps is disclosed in more detail below.

It should be noted that the steps iii), iv) and v) (viz. phases C and D)are preferably carried out in the same reactor, viz. in the samereaction mixture, directly following each other.

Preferably step iv) is carried out directly after step iii) in the samereactor. Preferably, step v) is carried out directly after step iv) inthe same reactor.

Step iv): Group 13- or Transition Metal Modification

The modification with Group 13- or transition metal, preferablyaluminum, ensures the presence of Group 13- or transition metal in theprocatalyst, in addition to magnesium (from the solid support) andtitanium (from the titanation treatment).

Without wishing to be bound by any particular theory, the presentinventors believe that one possible explanation is that the presence ofGroup 13- or transition metal increases the reactivity of the activesite and hence increases the yield of polymer.

Step iv) comprises modifying the third intermediate product obtained instep iii) with a modifier having the formula M(p)Xp, preferably MX₃,wherein M is a metal selected from the Group 13 metals and transitionmetals of the IUPAC periodic table of elements, p is the oxidation stateof M, and wherein X is a halide to yield a modified intermediateproduct. In case the oxidation state of M, e.g. aluminum, is three, M(p)is Al(III) and there are three monovalent halides X, e.g. AlCl₃ or AlF₃.In case the oxidation state of M, e.g. copper, is two, M(p) is Cu(II)and there are two monovalent halides X, CuBr₂ or CuCl₂. Step iv) ispreferably carried out directly after step iii), more preferably in thesame reactor and preferably in the same reaction mixture. In anembodiment, a mixture of aluminum trichloride and a solvent, e.g.chlorobenzene, is added to the reactor after step iii) has been carriedout. After the reaction has completed a solid is allowed to settle whichcan either be obtained by decanting or filtration and optionallypurified or a suspension of which in the solvent can be used for thefollowing step, viz. step v).

The metal modifier is preferably selected from the group of aluminummodifiers (e.g. aluminum halides), boron modifiers (e.g. boron halides),gallium modifiers (e.g. gallium halides), zinc modifiers (e.g. zinchalides), copper modifiers (e.g. copper halides), thallium modifiers(e.g. thallium halides), indium modifiers (e.g. indium halides),vanadium modifiers (e.g. vanadium halides), chromium modifiers (e.g.chromium halides) and iron modifiers (e.g. iron halides).

Examples of suitable modifiers are aluminum trichloride, aluminumtribromide, aluminum triiodide, aluminum trifluoride, boron trichloride,boron tribromide boron triiodide, boron trifluoride, galliumtrichloride, gallium tribromide, gallium triiodide, gallium trifluoride,zinc dichloride, zinc dibromide, zinc diiodide, zinc difluoride, copperdichloride, copper dibromide, copper diiodide, copper difluoride, copperchloride, copper bromide, copper iodide, copper fluoride, thalliumtrichloride, thallium tribromide, thallium triiodide, thalliumtrifluoride, thallium chloride, thallium bromide, thallium iodide,thallium fluoride, Indium trichloride, indium tribromide, indiumtriiodide, indium trifluoride, vanadium trichloride, vanadiumtribromide, vanadium triiodide, vanadium trifluoride, chromiumtrichloride, chromium dichloride, chromium tribromide, chromiumdibromide, iron dichloride, iron trichloride, iron tribromide, irondichloride, iron triiodide, iron diiodide, iron trifluoride and irondifluoride.

The amount of metal halide added during step iv) may vary according tothe desired amount of metal present in the procatalyst. It may forexample range between 0.1 to 5 wt. % based on the total weight of thesupport, preferably between 0.5 and 1.5 wt. %.

The metal halide is preferably mixed with a solvent prior to theaddition to the reaction mixture. The solvent for this step may beselected from for example aliphatic and aromatic hydrocarbons andhalogenated aromatic solvents with for instance 4-20 carbon atoms.Examples include toluene, xylene, benzene, decane, o-chlorotoluene andchlorobenzene. The solvent may also be a mixture or two or more thereof.

The duration of the modification step may vary from between 1 minute and120 minutes, preferably between 40 and 80 minutes, more preferablybetween 50 and 70 minutes. This time is dependent on the concentrationof the modifier, the temperature, the type of solvent used etc.

The modification step is preferably carried out at elevated temperatures(e.g. between 50 and 120° C., preferably between 90 and 110° C.).

The modification step may be carried out while stirring. The mixingspeed during the reaction depends on the type and the scale of thereactor used and the scale of the reactor used. The mixing speed can bedetermined by a person skilled in the art. As a non-limiting example,mixing may be carried at a stirring speed from 100 to 400 rpm,preferably from 150 to 300 rpm, more preferably about 200 rpm.

The wt/vol ratio for the metal halide and the solvent in step iv) isbetween 0.01 gram-0.1 gram: 5.0-100 ml.

The modified intermediate product is present in a solvent. It can bekept in that solvent after which the following step v) is directlycarried out. However, it can also be isolated and/or purified. The solidcan be allowed to settle by stopping the stirring. The supernatant maybe removed by decanting. Otherwise, filtration of the suspension is alsopossible. The solid product may be washed once or several times with thesame solvent used during the reaction or another solvent selected fromthe same group described above. The solid may be resuspended or may bedried or partially dried for storage.

Subsequent to this step, step v) is carried out to produce theprocatalyst according for use in a catalyst system according to anembodiment the present invention.

Step v): Titanation of Intermediate Product

This step is very similar to step iii). It relates to the additionaltitanation of the modified intermediate product. It is an additionalstage of contacting with catalytic species (viz. titanation in thisembodiment).

Step v) contacting said modified intermediate product obtained in stepiv) with a halogen-containing titanium compound to obtain theprocatalyst. When an activator is used during step iii) an internaldonor is used during this step.

Step v) is preferably carried out directly after step iv), morepreferably in the same reactor and preferably in the same reactionmixture.

In an embodiment, at the end of step iv) or at the beginning of step v)the supernatant is removed from the solid modified intermediate productobtained in step iv) by filtration or by decanting. To the remainingsolid, a mixture of titanium halide (e.g. tetrachloride) and a solvent(e.g. chlorobenzene) may be added. The reaction mixture is subsequentlykept at an elevated temperature (e.g. between 100 and 130° C., such as115° C.) for a certain period of time (e.g. between 10 and 120 minutes,such as between 20 and 60 minutes, e.g. 30 minutes). After this, a solidsubstance is allowed to settle by stopping the stirring.

The molar ratio of the transition metal to the magnesium preferably isbetween 10 and 100, most preferably, between 10 and 50.

Optionally, an internal electron donor is also present during this step.Also mixtures of internal electron donors can be used. Examples ofinternal electron donors are disclosed below. The molar ratio of theinternal electron donor relative to the magnesium may vary between widelimits, for instance between 0.02 and 0.75. Preferably, this molar ratiois between 0.05 and 0.4; more preferably between 0.1 and 0.4; and mostpreferably between 0.1 and 0.3.

The solvent for this step may be selected from for example aliphatic andaromatic hydrocarbons and halogenated aromatic solvents with forinstance 4-20 carbon atoms. The solvent may also be a mixture or two ormore thereof.

According to a preferred embodiment of the present invention this stepv) is repeated, in other words, the supernatant is removed as describedabove and a mixture of titanium halide (e.g. tetrachloride) and asolvent (e.g. chlorobenzene) is added. The reaction is continued atelevated temperatures during a certain time which can be same ordifferent from the first time step v) is carried out.

The step may be carried out while stirring. The mixing speed during thereaction depends on the type of reactor used and the scale of thereactor used. The mixing speed can be determined by a person skilled inthe art. This can be the same as discussed above for step iii).

Thus, step v) can be considered to consist of at least two sub steps inthis embodiment, being:

v-a) contacting said modified intermediate product obtained in step iv)with titanium tetrachloride—optionally using an internal donor—to obtaina partially titanated procatalyst; (this can e.g. be considered to bestage II as discussed above for a three-stage Phase C)v-b) contacting said partially titanated procatalyst obtained in stepv-a) with titanium tetrachloride to obtain the procatalyst. (this cane.g. be considered to be stage III as discussed above for a three-stagePhase C)

Additional sub steps can be present to increase the number of titanationsteps to four or higher (e.g. stages IV, V etc.)

The solid substance (procatalyst) obtained is washed several times witha solvent (e.g. heptane), preferably at elevated temperature, e.g.between 40 and 100° C. depending on the boiling point of the solventused, preferably between 50 and 70° C. After this, the procatalyst,suspended in solvent, is obtained. The solvent may be removed byfiltration or decantation. The procatalyst may be used as such wetted bythe solvent or suspended in solvent or it can be first dried, preferablypartly dried, for storage. Drying may e.g. be carried out by lowpressure nitrogen flow for several hours.

Thus in this embodiment, the total titanation treatment comprises threephases of addition of titanium halide. Wherein the first phase ofaddition is separated from the second and third phases of addition bythe modification with metal halide.

The titanation step (viz. the step of contacting with a titanium halide)according to this embodiment of the present invention is split into twoparts and a Group 13- or transition metal modification step isintroduced between the two parts or stages of the titanation.

Preferably, the first part of the titanation comprises one singletitanation step and the second part of the titanation comprises twosubsequent titanation steps. But different procedures may be used. Whenthis modification is carried out before the titanation step the increasein activity was higher as observed by the inventors. When thismodification is carried out after the titanation step the increase inactivity was less as observed by the present inventors.

In short, an embodiment of the present invention comprises the followingsteps: i) preparation of first intermediate reaction product; ii)activation of solid support to yield second intermediate reactionproduct; iii) first titanation or Stage I to yield third intermediatereaction product; iv) modification to yield modified intermediateproduct; v) second titanation or Stage II/111 to yield the procatalyst.This procatalyst is then combined with at least nPTES as an externaldonor and a co-catalyst to prepare the catalyst system according to thepresent invention.

The procatalyst may have a titanium, hafnium, zirconium, chromium orvanadium (preferably titanium) content of from about 0.1 wt. % to about6.0 wt. %, based on the total solids weight, or from about 1.0 wt. % toabout 4.5 wt. %, or from about 1.5 wt. % to about 3.5 wt. %. Weightpercent is based on the total weight of the procatalyst.

The weight ratio of titanium, hafnium, zirconium, chromium or vanadium(preferably titanium) to magnesium in the solid procatalyst may bebetween about 1:3 and about 1:160, or between about 1:4 and about 1:50,or between about 1:6 and 1:30.

The transition metal-containing solid catalyst compound according to thepresent invention comprises a transition metal halide (e.g. titaniumhalide, chromium halide, hafnium halide, zirconium halide or vanadiumhalide) supported on a metal or metalloid compound (e.g. a magnesiumcompound or a silica compound).

Preferably, a magnesium-based or magnesium-containing support is used inthe present invention. Such a support is prepared frommagnesium-containing support-precursors, such as magnesium halides,magnesium alkyls and magnesium aryls, and also magnesium alkoxy andmagnesium aryloxy compounds.

The support may be activated using activation compounds as described inmore detail above under Phase B.

The catalyst may further be activated during Phase C as discussed abovefor the process. This activation increases the yield of the resultingcatalyst composition in olefin polymerization.

Several activators can be used, such as benzamide, alkylbenzoates, andmonoesters. Each of these will be discussed below.

A benzamide activator has a structure according to Formula X:

R⁷⁰ and R⁷¹ are each independently selected from hydrogen or an alkyl,preferably an alkyl. Preferably, said alkyl has between 1 and 6 carbonatoms, more preferably between 1-3 carbon atoms. More preferably, R⁷⁰and R⁷¹ are each independently selected from hydrogen or methyl.

R⁷², R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ are each independently selected from hydrogen, aheteroatom (preferably a halide), or a hydrocarbyl group, selected e.g.from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups,and one or more combinations thereof. Said hydrocarbyl group may belinear, branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 10carbon atoms, more preferably between 1-8 carbon atoms, even morepreferably between 1 and 6 carbon atoms.

Suitable non-limiting examples of “benzamides” include benzamide (R⁷⁰and R⁷¹ are both hydrogen and each of R⁷², R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ arehydrogen) also denoted as BA-2H or methylbenzamide (R⁷⁰ is hydrogen; R⁷¹is methyl and each of R⁷², R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ are hydrogen) also denotedas BA-HMe or dimethylbenzamide (R⁷⁰ and R⁷¹ are methyl and each of R⁷²,R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ are hydrogen) also denoted as BA-2Me. Other examplesinclude monoethylbenzamide, diethylbenzamide, methylethylbenzamide, 2(trifluormethyl)benzamide, N,N-dimethyl-2-(trifluormethyl)benzamide, 3(trifluormethyl)benzamide, N,N-dimethyl-3-(trifluormethyl)benzamide,2,4-dihydroxy-N-(2-hydroxyethyl)benzamide,N-(1H-benzotriazol-1-ylmethyl)benzamide, 1-(4-ethylbenzoyl)piperazine,1-benzoylpiperidine.

It has surprisingly been found by the present inventors that when thebenzamide activator is added during the first stage of the processtogether with the catalytic species or directly after the addition ofthe catalytic species (e.g. within 5 minutes) an even higher increase inthe yield is observed compared to when the activator is added duringstage II or stage III of the process.

It has surprisingly been found by the present inventors that thebenzamide activator having two alkyl groups (e.g. dimethylbenzamide ordiethylbenzamide, preferably dimethylbenzamide) provides an even higherincrease in the yield than either benzamide or monoalkyl benzamide.

Without wishing to be bound by a particular theory the present inventorsbelieve that the fact that the most effective activation is obtainedwhen the benzamide activator is added during stage I has the followingreason. It is believed that the benzamide activator will bind thecatalytic species and is later on substituted by the internal donor whenthe internal donor is added.

Alkylbenzoates may be used as activators. The activator may hence beselected from the group alkylbenzoates having an alkylgroup havingbetween 1 and 10, preferably between 1 and 6 carbon atoms. Examples ofsuitable alkyl benzoates are methylbenzoate, ethylbenzoate according toFormula II, n-propylbenzoate, iso-propylbenzoate, n-butylbenzoate,2-butylbenzoate, t-butylbenzoate.

More preferably, the activator is ethylbenzoate. In a even morepreferred embodiment, ethylbenzoate as activator is added during stepiii) and a benzamide internal donor is added during step v), mostpreferably 4-[benzoyl(methyl)amino]pentan-2-yl benzoate according toFormula XII:

Monoesters may be used as activators. The monoester according to thepresent invention can be any ester of a monocarboxylic acid known in theart. The structures according to Formula V are also mono-esters but arenot explained in this section, see the section on Formula V. Themonoester can have the formula XXIII

R⁹⁴—CO—OR⁹⁵  Formula XXIII

R⁹⁴ and R⁹⁵ are each independently a hydrocarbyl group selected e.g.from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups,and one or more combinations thereof. R⁹⁴ may be a hydrogen. Saidhydrocarbyl group may be linear, branched or cyclic. Said hydrocarbylgroup may be substituted or unsubstituted. Said hydrocarbyl group maycontain one or more heteroatoms. Preferably, said hydrocarbyl group hasbetween 1 and 10 carbon atoms, more preferably between 1-8 carbon atoms,even more preferably between 1 and 6 carbon atoms. When R⁹⁴ is an aryl,this structure is similar to Formula V. Examples of aromatic monoestersare discussed with reference to Formula V.

Preferably, said monoester is an aliphatic monoester. Suitable examplesof mono-esters include formates, for instance, butyl formate; acetates,for instance ethyl acetate, amyl acetate and butyl acetate; acrylates,for instance ethyl acrylate, methyl methacrylate and isobutylmethacrylate. More preferably, the aliphatic monoester is an acetate.Most preferably, the aliphatic monoester is ethyl acetate.

In an embodiment, the monoester used in step iii) is an ester of analiphatic monocarboxylic acid having between 1 and 10 carbon atoms.Wherein R⁹⁴ is an aliphatic hydrocarbyl group.

The molar ratio between the monoester in step iii) and Mg may range from0.05 to 0.5, preferably from 0.1 to 0.4, and most preferably from 0.15to 0.25.

The monoester is not used as a stereospecificity agent, like usualinternal donors are known to be in the prior art. The monoester is usedas an activator.

Without to be bound by any theory, the inventors believe that themonoester used in the process according to the present inventionparticipates at the formation of the magnesium halogen (e.g. MgCl₂)crystallites during the interaction of Mg-containing support withtitanium halogen (e.g. TiCl₄). The monoester may form intermediatecomplexes with Ti and Mg halogen compounds (for instance, TiCl₄,TiCl₃(OR), MgCl₂, MgCl(OEt), etc.), help to the removal of titaniumproducts from solid particles to mother liquor and affect the activityof final catalyst. Therefore, the monoester according to the presentinvention can also be referred to as an activator.

As used herein, an “internal electron donor” or an “internal donor” is acompound added during formation of the procatalyst that donates a pairof electrons to one or more metals present in the resultant procatalyst.Not bounded by any particular theory, it is believed that the internalelectron donor assists in regulating the formation of active sitesthereby enhancing catalyst stereoselectivity.

The internal electron donor can be any compound known in the art to beused as internal electron donor. Suitable examples of internal donorsinclude aromatic acid esters, such as monocarboxylic acid ester ordicarboxylic acid esters (e.g. ortho-dicarboxylic acid esters such asphthalic acid esters), (N-alkyl)amidobenzoates, 1,3-diethers, silylesters, fluorenes, succinates and/or combinations thereof.

It is preferred to use so-called phthalate free internal donors becauseof increasingly stricter government regulations about the maximumphthalate content of polymers. This leads to an increased demand inphthalate free catalyst compositions. In the context of the presentinvention, “essentially phthalate-free” of “phthalate-free” means havinga phthalate content of less than for example 150 ppm, alternatively lessthan for example 100 ppm, alternatively less than for example 50 ppm,alternatively for example less than 20 ppm.

An aromatic acid ester can be used as internal donor. As used herein, an“aromatic acid ester” is a monocarboxylic acid ester (also called“benzoic acid ester”) as shown in Formula V, a dicarboxylic acid ester(e.g. an o-dicarboxylic acid also called “phthalic acid ester”) as shownin Formula VI:

R³⁰ is selected from a hydrocarbyl group independently selected e.g.from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups,and one or more combinations thereof. Said hydrocarbyl group may belinear, branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 10carbon atoms, more preferably between 1-8 carbon atoms, even morepreferably between 1 and 6 carbon atoms. Suitable examples ofhydrocarbyl groups include alkyl-, cycloalkyl-, alkenyl-, alkadienyl-,cycloalkenyl-, cycloalkadienyl-, aryl-, aralkyl, alkylaryl, andalkynyl-groups.

R³¹, R³², R³³, R³⁴, R³⁵ are each independently selected from hydrogen, aheteroatom (preferably a halide), or a hydrocarbyl group, selected frome.g. alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups,and one or more combinations thereof. Said hydrocarbyl group may belinear, branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 10carbon atoms, more preferably between 1-8 carbon atoms, even morepreferably between 1 and 6 carbon atoms.

Suitable non-limiting examples of “benzoic acid esters” include an alkylp-alkoxybenzoate (such as ethyl p-methoxybenzoate, methylp-ethoxybenzoate, ethyl p-ethoxybenzoate), an alkyl benzoate (such asethyl benzoate, methyl benzoate), an alkyl p-halobenzoate (ethylp-chlorobenzoate, ethyl p-bromobenzoate), and benzoic anhydride. Thebenzoic acid ester is preferably selected from ethyl benzoate, benzoylchloride, ethyl p-bromobenzoate, n-propyl benzoate and benzoicanhydride. The benzoic acid ester is more preferably ethyl benzoate.

R⁴⁰ and R⁴¹ are each independently a hydrocarbyl group selected e.g.from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups,and one or more combinations thereof. Said hydrocarbyl group may belinear, branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 10carbon atoms, more preferably between 1-8 carbon atoms, even morepreferably between 1 and 6 carbon atoms. Suitable examples ofhydrocarbyl groups include alkyl-, cycloalkyl-, alkenyl-, alkadienyl-,cycloalkenyl-, cycloalkadienyl-, aryl-, aralkyl, alkylaryl, andalkynyl-groups.

R⁴², R⁴³, R⁴⁴, R⁴⁵ are each independently selected from hydrogen, ahalide or a hydrocarbyl group, selected e.g. from alkyl, alkenyl, aryl,aralkyl, alkoxycarbonyl or alkylaryl groups, and one or morecombinations thereof. Said hydrocarbyl group may be linear, branched orcyclic. Said hydrocarbyl group may be substituted or unsubstituted. Saidhydrocarbyl group may contain one or more heteroatoms. Preferably, saidhydrocarbyl group has between 1 and 10 carbon atoms, more preferablybetween 1-8 carbon atoms, even more preferably between 1 and 6 carbonatoms.

Suitable non-limiting examples of phthalic acid esters include dimethylphthalate, diethyl phthalate, di-n-propyl phthalate, diisopropylphthalate, di-n-butyl phthalate, diisobutyl phthalate, di-t-butylphthalate, diisoamyl phthalate, di-t-amyl phthalate, dineopentylphthalate, di-2-ethylhexyl phthalate, di-2-ethyldecyl phthalate,bis(2,2,2-trifluoroethyl) phthalate, diisobutyl 4-t-butylphthalate, anddiisobutyl 4-chlorophthalate. The phthalic acid ester is preferablydi-n-butyl phthalate or diisobutyl phthalate.

As used herein a “di-ether” may be a 1,3-di(hydrocarboxy)propanecompound, optionally substituted on the 2-position represented by theFormula VII,

R⁵¹ and R⁵² are each independently selected from a hydrogen or ahydrocarbyl group selected e.g. from alkyl, alkenyl, aryl, aralkyl,alkoxycarbonyl or alkylaryl groups, and one or more combinationsthereof. Said hydrocarbyl group may be linear, branched or cyclic. Saidhydrocarbyl group may be substituted or unsubstituted. Said hydrocarbylgroup may contain one or more heteroatoms. Preferably, said hydrocarbylgroup has between 1 and 10 carbon atoms, more preferably between 1-8carbon atoms, even more preferably between 1 and 6 carbon atoms.Suitable examples of hydrocarbyl groups include alkyl-, cycloalkyl-,alkenyl-, alkadienyl-, cycloalkenyl-, cycloalkadienyl-, aryl-, aralkyl,alkylaryl, and alkynyl-groups.

R⁵³ and R⁵⁴ are each independently selected from a hydrocarbyl group,selected e.g. from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl oralkylaryl groups, and one or more combinations thereof. Said hydrocarbylgroup may be linear, branched or cyclic. Said hydrocarbyl group may besubstituted or unsubstituted. Said hydrocarbyl group may contain one ormore heteroatoms. Preferably, said hydrocarbyl group has between 1 and10 carbon atoms, more preferably between 1-8 carbon atoms, even morepreferably between 1 and 6 carbon atoms.

Suitable examples of dialkyl diether compounds include1,3-dimethoxypropane, 1,3-diethoxypropane, 1,3-dibutoxypropane,1-methoxy-3-ethoxypropane, 1-methoxy-3-butoxypropane,1-methoxy-3-cyclohexoxypropane, 2,2-dimethyl-1,3-dimethoxypropane,2,2-diethyl-1,3-dimethoxypropane, 2,2-di-n-butyl-1,3-dimethoxypropane,2,2-diiso-butyl-1,3-dimethoxypropane,2-ethyl-2-n-butyl-1,3-dimethoxypropane,2-n-propyl-2-cyclopentyl-1,3-dimethoxypropane,2,2-dimethyl-1,3-diethoxypropane,2-n-propyl-2-cyclohexyl-1,3-diethoxypropane,2-(2-ethylhexyl)-1,3-dimethoxypropane, 2-isopropyl-1,3-dimethoxypropane,2-n-butyl-1,3-dimethoxypropane, 2-sec-butyl-1,3-dimethoxypropane,2-cyclohexyl-1,3-dimethoxypropane, 2-phenyl-1,3-diethoxypropane,2-cumyl-1,3-diethoxypropane, 2-(2-phenyllethyl)-1,3-dimethoxypropane,2-(2-cyclohexylethyl)-1,3-dimethoxypropane,2-(p-chlorophenyl)-1,3-dimethoxypropane,2-(diphenylmethyl)-1,3-dimethoxypropane,2-(1-naphthyl)-1,3-dimethoxypropane,2-(fluorophenyl)-1,3-dimethoxypropane,2-(1-decahydronaphthyl)-1,3-dimethoxypropane,2-(p-t-butylphenyl)-1,3-dimethoxypropane,2,2-dicyclohexyl-1,3-dimethoxypropane,2,2-di-n-propyl-1,3-dimethoxypropane,2-methyl-2-n-propyl-1,3-dimethoxypropane,2-methyl-2-benzyl-1,3-dimethoxypropane,2-methyl-2-ethyl-1,3-dimethoxypropane,2-methyl-2-phenyl-1,3-dimethoxypropane,2-methyl-2-cyclohexyl-1,3-dimethoxypropane,2,2-bis(p-chlorophenyl)-1,3-dimethoxypropane,2,2-bis(2-cyclohexylethyl)-1,3-dimethoxypropane,2-methyl-2-isobutyl-1,3-dimethoxypropane,2-methyl-2-(2-ethylhexyl)-1,3-dimethoxy propane,2-methyl-2-isopropyl-1,3-dimethoxypropane,2,2-diphenyl-1,3-dimethoxypropane, 2,2-dibenzyl-1,3-dimethoxypropane,2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane,2,2-diisobutyl-1,3-diethoxypropane,2,2-diisobutyl-1,3-di-n-butoxypropane,2-isobutyl-2-isopropyl-1,3-dimethoxypropane,2,2-di-sec-butyl-1,3-dimethoxypropane,2,2-di-t-butyl-1,3-dimethoxypropane,2,2-dineopentyl-1,3-dimethoxypropane,2-isopropyl-2-isopentyl-1,3-dimethoxypropane,2-phenyl-2-benzyl-1,3-dimethoxypropane,2-cyclohexyl-2-cyclohexylmethyl-1,3-dimethoxypropane, 2-isopropyl-2-(3,7-dimethyloctyl) 1,3-dimethoxypropane,2,2-diisopropyl-1,3-dimethoxypropane,2-isopropyl-2-cyclohexylmethyl-1,3-dimethoxypropane,2,2-diisopentyl-1,3-dimethoxypropane,2-isopropyl-2-cyclohexyl-1,3-dimethoxypropane,2-isopropyl-2-cyclopentyl-1,3-dimethoxypropane,2,2-dicylopentyl-1,3-dimethoxypropane,2-n-heptyl-2-n-pentyl-1,3-dimethoxypropane,9,9-bis(methoxymethyl)fluorene,1,3-dicyclohexyl-2,2-bis(methoxymethyl)propane,3,3-bis(methoxymethyl)-2,5-dimethylhexane, or any combination of theforegoing. In an embodiment, the internal electron donor is1,3-dicyclohexyl-2,2-bis(methoxymethyl)propane,3,3-bis(methoxymethyl)-2,5-dimethylhexane,2,2-dicyclopentyl-1,3-dimethoxypropane and combinations thereof.

Examples of preferred ethers are diethyl ether, dibutyl ether, diisoamylether, anisole and ethylphenyl ether, 2,3-dimethoxypropane,2,3-dimethoxypropane, 2-ethyl-2-butyl-1,3-dimethoxypropane,2-isopropyl-2-isopentyl-1,3-dimethoxypropane and 9,9-bis (methoxymethyl)fluorene:

As used herein a “succinate acid ester” is a 1,2-dicarboxyethane and canbe used as internal donor.

R⁶⁰ and R⁶¹ are each independently a hydrocarbyl group, selected e.g.from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups,and one or more combinations thereof. Said hydrocarbyl group may belinear, branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 10carbon atoms, more preferably between 1-8 carbon atoms, even morepreferably between 1 and 6 carbon atoms.

R⁶², R⁶³, R⁶⁴ and R⁶⁵ are each independently selected from hydrogen or ahydrocarbyl group, selected e.g. from alkyl, alkenyl, aryl, aralkyl,alkoxycarbonyl or alkylaryl groups, and one or more combinationsthereof. Said hydrocarbyl group may be linear, branched or cyclic. Saidhydrocarbyl group may be substituted or unsubstituted. Said hydrocarbylgroup may contain one or more heteroatoms. Preferably, said hydrocarbylgroup has between 1 and 20 carbon atoms.

More preferably, R⁶², R⁶³, R⁶⁴ and R⁶⁵ are independently selected from agroup consisting of hydrogen, C₁-C₁₀ straight and branched alkyl; C₃-C₁₀cycloalkyl; C₆-C₁₀ aryl; and C₇-C₁₀ alkaryl and aralkyl group.

Even more preferably, R⁶², R⁶³, R⁶⁴ and R⁶⁵ are independently selectedfrom a group consisting of hydrogen, methyl, ethyl, n-propyl,iso-propyl, n-butyl, sec-butyl, iso-butyl, t-butyl, phenyltrifluoromethyl and halophenyl group. Most preferably, one of R⁶² andR⁶³ is selected from methyl, ethyl, n-propyl, iso-propyl, n-butyl,sec-butyl, iso-butyl, t-butyl, whereas the other is a hydrogen atom; andone of R⁶⁴ and R⁶⁵ is selected from methyl, ethyl, n-propyl, iso-propyl,n-butyl, sec-butyl, iso-butyl, t-butyl, whereas the other is a hydrogenatom.

Suitable examples of succinate acid ester include diethyl2,3-di-isopropylsuccinate, diethyl 2,3-di-n-propylsuccinate, diethyl2,3-di-isobutylsuccinate, diethyl 2,3-di-sec-butylsuccinate, dimethyl2,3-di-isopropylsuccinate, dimethyl 2,3-di-n-propylsuccinate,dimethyl-2,3-di-isobutylsuccinate, dimethyl 2,3-di-sec-butylsuccinate.

Examples of other organic compounds containing a heteroatom arethiophenol, 2-methylthiophene, isopropyl mercaptan, diethylthioether,diphenylthio-ether, tetrahydrofuran, dioxane, anisole, acetone,triphenylphosphine, triphenylphosphite, diethylphosphate anddiphenylphosphate.

The silyl ester as internal donor can be any silyl ester or silyl diolester known in the art, for instance as disclosed in US 2010/0130709.

When an aminobenzoate (AB) according to Formula XI is used as aninternal donor this ensures a better control of stereochemistry andallows preparation of polyolefins having a broader molecular weightdistribution.

Aminobenzoates suitable as internal donor according to the presentinvention are the compounds represented by Formula XI:

Wherein R⁸⁰ is an aromatic group, selected from aryl or alkylaryl groupsand may be substituted or unsubstituted. Said aromatic group may containone or more heteroatoms. Preferably, said aromatic group has between 6and 20 carbon atoms. It should be noted that the two R⁸⁰ groups may bethe same but may also be different.

R⁸⁰ can be the same or different than any of R⁸¹-R⁸⁷ and is preferablyan aromatic substituted and unsubstituted hydrocarbyl having 6 to 10carbon atoms.

More preferably, R⁸⁰ is selected from the group consisting of C₆-C₁₀aryl unsubstituted or substituted with e.g. an acylhalide or analkoxyde; and C₇-C₁₀ alkaryl and aralkyl group; for instance,4-methoxyphenyl, 4-chlorophenyl, 4-methylphenyl.

Particularly preferred, R⁸⁰ is substituted or unsubstituted phenyl,benzyl, naphthyl, ortho-tolyl, para-tolyl oranisol group. Mostpreferably, R⁸⁰ is phenyl.

R⁸¹, R⁸², R⁸³, R⁸⁴, R⁸⁵, and R⁸⁶ are each independently selected fromhydrogen or a hydrocarbyl group, selected e.g. from alkyl, alkenyl,aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one or morecombinations thereof. Said hydrocarbyl group may be linear, branched orcyclic. Said hydrocarbyl group may be substituted or unsubstituted. Saidhydrocarbyl group may contain one or more heteroatoms. Preferably, saidhydrocarbyl group has between 1 and 20 carbon atoms.

More preferably, R⁸¹, R⁸², R⁸³, R⁸⁴, R⁸⁵, and R⁸⁶ are independentlyselected from a group consisting of hydrogen, C₁-C₁₀ straight andbranched alkyl; C₃-C₁₀ cycloalkyl; C₆-C₁₀ aryl; and C₇-C₁₀ alkaryl andaralkyl group.

Even more preferably, R⁸¹, R⁸², R⁸³, R⁸⁴, R⁸⁵ and R⁸⁶ are independentlyselected from a group consisting of hydrogen, methyl, ethyl, propyl,isopropyl, butyl, t-butyl, phenyl, trifluoromethyl and halophenyl group.

Most preferably, R⁸¹, R⁸², R⁸³, R⁸⁴, R⁸⁵, and R⁸⁶ are each hydrogen,methyl, ethyl, propyl, t-butyl, phenyl or trifluoromethyl.

Preferably, R⁸¹ and R⁸² is each a hydrogen atom.

More preferably, R⁸¹ and R⁸² is each a hydrogen atom and each of R⁸³,R⁸⁴, R⁸⁵, and R⁸⁶ is selected from the group consisting of hydrogen,C₁-C₁₀ straight and branched alkyls; C₃-C₁₀ cycloalkyls; C₆-C₁₀ aryls;and C₇-C₁₀ alkaryl and aralkyl group.

Preferably, at least one of R⁸³ and R⁸⁴ and at least one of R⁸⁵ and R⁸⁶is a hydrocarbyl group having at least one carbon atom, being selectedfrom the group as defined above.

More preferably, when at least one of R⁸³ and R⁸⁴ and one of R⁸⁵ and R⁸⁶is a hydrocarbyl group having at least one carbon atom then the otherone of R₃ and R₄ and of R⁸⁵ and R⁸⁶ is each a hydrogen atom.

Most preferably, when one of R⁸³ and R⁸⁴ and one of R⁸⁵ and R⁸⁶ is ahydrocarbyl group having at least one carbon atom, then the other one ofR⁸³ and R⁸⁴ and of R⁸⁵ and R⁸⁶ is each a hydrogen atom and R⁸¹ and R⁸²is each a hydrogen atom.

Preferably, R⁸¹ and R⁸² is each a hydrogen atom and one of R⁸³ and R⁸⁴and one of R⁸⁵ and R⁸⁶ is selected from the group consisting of C₁-C₁₀straight and branched alkyl; C₃-C₁₀ cycloalkyl; C₆-C₁₀ aryl; and C₇-C₁₀alkaryl and aralkyl group;

More preferably R⁸⁵ and R⁸⁶ is selected from the group consisting ofC₁-C₁₀ alkyl, such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl,phenyl, trifluoromethyl and halophenyl group; and most preferably, oneof R⁸³ and R⁸⁴, and one of R⁸⁵ and R⁸⁶ is methyl

R⁸⁷ is a hydrogen or a hydrocarbyl group, selected e.g. from alkyl,alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one ormore combinations thereof. Said hydrocarbyl group may be linear,branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 20carbon atoms, more preferably between 1 and carbon atoms. R⁸⁷ may be thesame or different than any of R⁸¹, R⁸², R⁸³, R⁸⁴, R⁸⁵, and R⁸⁶ with theprovision that R⁸⁷ is not a hydrogen atom.

More preferably, R⁸⁷ is selected from a group consisting of C₁-C₁₀straight and branched alkyl; C₃-C₁₀ cycloalkyl; C₆-C₁₀ aryl; and C₇-C₁₀alkaryl and aralkyl group.

Even more preferably, R⁸⁷ is selected from a group consisting of methyl,ethyl, propyl, isopropyl, butyl, t-butyl, phenyl, benzyl and substitutedbenzyl and halophenyl group.

Most preferably, R⁸⁷ is methyl, ethyl, propyl, isopropyl, benzyl orphenyl; and even most preferably, R⁸⁷ is methyl, ethyl or propyl.

Without being limited thereto, particular examples of the compounds offormula (XI) are the structures as depicted in formulas (XII)-(XXII).For instance, the structure in Formula (XII) may correspond to4-[benzoyl(methyl)amino]pentan-2-yl benzoate; Formula (XIII) to3-[benzoyl(cyclohexyl)amino]-1-phenylbutyl benzoate; Formula (XIV) to3-[benzoyl(propan-2-yl)amino]-1-phenylbutyl benzoate; Formula (XV) to4-[benzoyl(propan-2-yl)amino]pentan-2-yl benzoate; Formula (XVI) to4-[benzoyl(methyl)amino]-1,1,1-trifluoropentan-2-yl benzoate; Formula(XVII) to 3-(methylamino)-1,3-diphenylpropan-1-oldibenzoate; Formula(XVIII) to 2,2,6,6-tetramethyl-5-(methylamino)heptan-3-ol dibenzoate;Formula (XIX) to 4-[benzoyl (ethyl)amino]pentan-2-yl benzoate; Formula(XX) to 3-(methyl)amino-propan-1-ol dibenzoate; Formula (XXI) to3-(methyl)amino-2,2-dimethylpropan-1-ol dibenzoate; Formula (XXII) to4-(methylamino)pentan-2-yl bis (4-methoxy)benzoate).

It has been surprisingly found that the catalyst composition comprisingthe compound of formula (XI) as an internal electron donor shows bettercontrol of stereochemistry and allows preparation of polyolefins,particularly of polypropylenes having broader molecular weightdistribution and higher isotacticity.

Preferably, the catalyst composition according to the inventioncomprises the compound having formula (XI) as the only internal electrondonor in a Ziegler-Natta catalyst composition.

The compounds of formula (XII), (XIX), (XXII) and (XVIII) are the mostpreferred internal electron donors in the catalyst composition accordingto the present invention as they allow preparation of polyolefins havingbroader molecular weight distribution and higher isotacticity. The lowmelt flow range values (MFR) of the polymers obtained by using thecatalyst compositions according to the present invention, i.e. MFR lowerthan 6 dg/min, lower than 4 dg/min and even lower than 3 dg/min indicateimproved process stability in terms of producing polymers having stableMFR values.

The compound according to formula (XI) can be made by any method knownin the art. In this respect, reference is made to J. Chem. Soc. Perkintrans. 1 1994, 537-543 and to Org. Synth. 1967, 47, 44. These documentsdisclose a step a) of contacting a substituted 2,4-diketone with asubstituted amine in the presence of a solvent to give aβ-enaminoketone; followed by a step b) of contacting the β-enaminoketonewith a reducing agent in the presence of a solvent to give aγ-aminoalcohol. The substituted 2,4-diketone and the substituted aminecan be applied in step a) in amounts ranging from 0.5 to 2.0 mole,preferably from 1.0 to 1.2 mole. The solvent in steps a) and b) may beadded in an amount of 5 to 15 volume, based on the total amount of thediketone, preferably of 3 to 6 volume. The β-enaminoketone to diketonemole ratio in step b) may be of from 0.5 to 6, preferably from 1 to 3.The reducing agent to β-enaminoketone mole ratio in step b) may be offrom 3 to 8, preferably from 4 to 6; the reducing agent may be selectedfrom the group comprising metallic sodium, NaBH₄ in acetic acid, Ni—Alalloy. Preferably, the reducing agent is metallic sodium because it is acheap reagent.

The γ-aminoalcohol that can be used for making compound (XI) can besynthesized as described in the literature and also mentioned hereinabove or this compound can be directly purchased commercially and usedas a starting compound in a reaction to obtain the compound representedby formula (XI). Particularly, the γ-aminoalcohol can be reacted with asubstituted or unsubstituted benzoyl chloride in the presence of a baseto obtain the compound represented by formula (XI)(referred herein alsoas step c), regardless that γ-aminoalcohol was synthesized as describedin the literature or commercially purchased). The molar ratio betweenthe substituted or unsubstituted benzoyl chloride and the γ-aminoalcoholmay range from 2 to 4, preferably from 2 to 3. The base may be any basicchemical compound that is able to deprotonate the γ-aminoalcohol. Saidbase can have a pK_(a) of at least 5; or at least 10 or preferablybetween 5 and 40, wherein pK_(a) is a constant already known to theskilled person as the negative logarithm of the acid dissociationconstant k_(a). Preferably, the base is pyridine; a trialkyl amine, e.g.triethylamine; or a metal hydroxide e.g. NaOH, KOH. Preferably, the baseis pyridine. The molar ratio between the base and the γ-aminoalcohol mayrange from 3 to 10, preferably from 4 to 6.

The solvent used in any of steps a), b) and c) can be selected from anyorganic solvents, such as toluene, dichloromethane, 2-propanol,cyclohexane or mixtures of any organic solvents. Preferably, toluene isused in each of steps a), b) and c). More preferably, a mixture oftoluene and 2-propanol is used in step b). The solvent in step c) can beadded in an amount of 3 to 15 volume, preferably from 5 to 10 volumebased on the γ-aminoalcohol.

The reaction mixture in any of steps a), b) and c) may be stirred byusing any type of conventional agitators for more than about 1 hour,preferably for more than about 3 hours and most preferably for more thanabout 10 hours, but less than about 24 hours. The reaction temperaturein any of steps a) and b) may be the room temperature, i.e. of fromabout 15 to about 30° C., preferably of from about 20 to about 25° C.The reaction temperature in step c) may range between 0 and 10° C.,preferably between 5 and 10° C. The reaction mixture in any of steps a),b) and c) may be refluxed for more than about 10 hours, preferably formore than about 20 hours but less than about 40 hours or until thereaction is complete (reaction completion may be measured by GasChromatography, GC).

The reaction mixture of steps a) and b) may be then allowed to cool toroom temperature, i.e. at a temperature of from about 15 to about 30°C., preferably of from about 20 to about 25° C. The solvent and anyexcess of components may be removed in any of steps a), b) and c) by anymethod known in the art, such as evaporation or washing. The obtainedproduct in any of steps b) and c) can be separated from the reactionmixture by any method known in the art, such as by extraction over metalsalts, e.g. sodium sulfate.

The molar ratio of the internal donor of formula (XI) relative to themagnesium can be from 0.02 to 0.5. Preferably, this molar ratio isbetween 0.05 and 0.2.

A benzamide can be used as internal donor. Suitable compounds have astructure according to formula X:

R⁷⁰ and R⁷¹ are each independently selected from hydrogen or an alkyl.Preferably, said alkyl has between 1 and 6 carbon atoms, more preferablybetween 1-3 carbon atoms. More preferably, R⁷⁰ and R⁷¹ are eachindependently selected from hydrogen or methyl.

R⁷², R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ are each independently selected from hydrogen, aheteroatom (preferably a halide), or a hydrocarbyl group, selected e.g.from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups,and one or more combinations thereof. Said hydrocarbyl group may belinear, branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 10carbon atoms, more preferably between 1-8 carbon atoms, even morepreferably between 1 and 6 carbon atoms.

Suitable non-limiting examples of “benzamides” include benzamide (R⁷⁰and R⁷¹ are both hydrogen and each of R⁷², R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ arehydrogen) also denoted as BA-2H or methylbenzamide (R⁷⁰ is hydrogen; R⁷¹is methyl and each of R⁷², R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ are hydrogen) also denotedas BA-HMe or dimethylbenzamide (R⁷⁰ and R⁷¹ are methyl and each of R⁷²,R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ are hydrogen) also denoted as BA-2Me. Other examplesinclude monoethylbenzamide, diethylbenzamide, methylethylbenzamide,2-(trifluormethyl)-benzamide, N,N-dimethyl-2-(trifluormethyl)benzamide,3-(trifluormethyl)benzamide, N,N-dimethyl-3-(trifluormethyl)benzamide,2,4-dihydroxy-N-(2-hydroxyethyl)benzamide,N-(1H-benzotriazol-1-ylmethyl)benzamide, 1-(4-ethylbenzoyl)piperazine,1-benzoylpiperidine.

As discussed in WO 2013124063 1,5-diesters according to Formula XXV canbe used as internal donors. These 1,5-diesters have two chiral centerson their C2 and C4 carbon atoms. Four isomers exist, being the 2R, 4Smeso isomer, the 2S, 4R meso isomers and the 2S, 4S and 2R, 4R isomers.A mixture of all of them is called “rac” diester.

R¹⁵ is independently a hydrocarbyl group independently selected e.g.from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups,and one or more combinations thereof. Said hydrocarbyl group may belinear, branched or cyclic. Said hydrocarbyl group may be substituted orunsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 20carbon atoms.

R¹⁶ and R¹⁷ are different with respect to each other. Both R¹⁶ groupsmay be the same or different. Both R¹⁷ groups may be the same ordifferent. The R¹⁶ and R¹⁷ groups and independently selected from thegroup consisting of hydrogen, halogen, and hydrocarbyl groupindependently selected e.g. from alkyl, alkenyl, aryl, aralkyl,alkoxycarbonyl or alkylaryl groups, and one or more combinationsthereof. Said hydrocarbyl group may be linear, branched or cyclic. Saidhydrocarbyl group may be substituted or unsubstituted. Said hydrocarbylgroup may contain one or more heteroatoms. Preferably, said hydrocarbylgroup has between 1 and 20 carbon atoms.

An example of a compound according to formula XXV is pentanedioldibenzoate.

The compound according to Formula XXV has two stereocenters (at C2 andC4), comprises two so-called stereocenters each giving rise to twodifferent configurations and thus to a total of four stereoisomers.There are two sets of diastereomers (or diastereoisomers), eachcomprising two enantiomers. Enantiomers differ in both stereocenters andare therefore mirror images of one another.

The R¹⁶ and the R¹⁷ groups may be switched in position. In other words,the mirror image of the compound of Formula XXV having the two R¹⁷groups on the left hand of the structure. The compound in formula XXV isthe (2R, 4S) meso-isomer whereas the mirror image (not shown) is the(2S, 4R) meso-isomer. The compound of Formula XXV is a meso-isomer, i.e.it contains two stereocenters (chiral centers) but it is not chiral.

The following two other isomers are possible: a (2S, 4S)-isomer (notshown), a (2R, 4R)-isomer (not shown). R and S illustrate the chiralcenters of the molecules, as known to the skilled person. When a mixtureof 2S, 4S and 2R, 4R is present, this is called “rac”. These internaldonors are disclosed in detail in WO 2013/124063 which shows Fisherprojections of all isomers.

In an embodiment, at least one group of R¹⁶ and R¹⁷ may be selected fromthe group consisting of hydrogen, halogen, C1-C10 linear or branchedalkyl, C3-C10 cycloalkyl, C6-C10 aryl, and C7-C10 alkaryl or aralkylgroup. More preferably, at least one group of R¹⁶ and R¹⁷ is selectedfrom the group consisting of hydrogen, methyl, ethyl, propyl, isopropyl,butyl, t-butyl, phenyl, and halophenyl group.

Preferably, either R¹⁶ and R¹⁷ represents hydrogen. More preferably, R¹⁶and R¹⁷ represent a methyl or an ethyl group. Particularly preferred iswhen either of R¹⁶ and R¹⁷ represents hydrogen and the other R¹⁶ and R¹⁷represents a methyl or an ethyl group.

R¹⁵ is preferably independently selected from benzene-ring containinggroups, such as phenyl, phenyl substituted by alkyl, alkoxy or halogen;optionally the carbon atom(s) on the benzene ring being replaced by ahetero-atom of oxygen atom and/or nitrogen atom; alkenyl or phenylsubstituted alkenyl, such as vinyl, propenyl, styryl; alkyl, such asmethyl, ethyl, propyl, etc.

More preferably, R¹⁵ represents a phenyl group. Particularly preferredis meso pentane-2,4-diol dibenzoate (mPDDB).

The catalyst system according to the present invention includes aco-catalyst. As used herein, a “co-catalyst” is a term well-known in theart in the field of Ziegler-Natta catalysts and is recognized to be asubstance capable of converting the procatalyst to an activepolymerization catalyst. Generally, the co-catalyst is an organometalliccompound containing a metal from group 1, 2, 12 or 13 of the PeriodicSystem of the Elements (Handbook of Chemistry and Physics, 70th Edition,CRC Press, 1989-1990).

The co-catalyst may include any compounds known in the art to be used as“co-catalysts”, such as hydrides, alkyls, or aryls of aluminum, lithium,zinc, tin, cadmium, beryllium, magnesium, and combinations thereof. Theco-catalyst may be a hydrocarbyl aluminum co-catalyst represented by theformula R²⁰ ₃Al.

R²⁰ is independently selected from a hydrogen or a hydrocarbyl, selectede.g. from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylarylgroups, and one or more combinations thereof. Said hydrocarbyl group maybe linear, branched or cyclic. Said hydrocarbyl group may be substitutedor unsubstituted. Said hydrocarbyl group may contain one or moreheteroatoms. Preferably, said hydrocarbyl group has between 1 and 20carbon atoms, more preferably between 1-12 carbon atoms, even morepreferably between 1 and 6 carbon atoms. On the proviso that at leastone R²⁰ is a hydrocarbyl group. Optionally, two or three R²⁰ groups arejoined in a cyclic radical forming a heterocyclic structure.

Non-limiting examples of suitable R²⁰ groups are: methyl, ethyl, propyl,isopropyl, butyl, isobutyl, t-butyl, pentyl, neopentyl, hexyl,2-methylpentyl, heptyl, octyl, isooctyl, 2-ethylhexyl,5,5-dimethylhexyl, nonyl, decyl, isodecyl, undecyl, dodecyl, phenyl,phenethyl, methoxyphenyl, benzyl, tolyl, xylyl, naphthyl, methylnapthyl,cyclohexyl, cycloheptyl, and cyclooctyl.

Suitable examples of the hydrocarbyl aluminum compounds as co-catalystinclude triisobutylaluminum (TIBA), trihexylaluminum,di-isobutylaluminum hydride (DIBALH), dihexylaluminum hydride,isobutylaluminum dihydride, hexylaluminum dihydride,diisobutylhexylaluminum, isobutyl dihexylaluminum, trimethylaluminum,triethylaluminum, tripropylaluminum, triisopropylaluminum,tri-n-butylaluminum, trioctylaluminum, tridecylaluminum,tridodecylaluminum, tribenzylaluminum, triphenylaluminum,trinaphthylaluminum, and tritolylaluminum. In an embodiment, theco-catalyst is selected from triethylaluminum, triisobutylaluminum,trihexylaluminum, di-isobutylaluminum hydride and dihexylaluminumhydride. More preferably, trimethylaluminum, triethylaluminum,triisobutylaluminum, and/or trioctylaluminum. Most preferably,triethylaluminum (abbreviated as TEAL).

The co-catalyst can also be a hydrocarbyl aluminum compound representedby the formula R²¹ _(m)AlX²¹ _(3-m).

R²¹ is an alkyl group. Said alkyl group may be linear, branched orcyclic. Said alkyl group may be substituted or unsubstituted.Preferably, said alkyl group has between 1 and 20 carbon atoms, morepreferably between 1-12 carbon atoms, even more preferably between 1 and6 carbon atoms.

Non-limiting examples of suitable R²¹ groups are: methyl, ethyl, propyl,isopropyl, butyl, isobutyl, t-butyl, pentyl, neopentyl, hexyl,2-methylpentyl, heptyl, octyl, isooctyl, 2-ethylhexyl,5,5-dimethylhexyl, nonyl, decyl, isodecyl, undecyl, and dodecyl.

X²¹ is selected from the group of consisting of fluoride (F—), chloride(Cl—), bromide (Br—) or iodide (I—) or an alkoxide (RO—). The value form is preferably 1 or 2.

Non-limiting examples of suitable alkyl aluminum halide compounds forco-catalyst include tetraethyl-dialuminoxane, methylaluminoxane,isobutylaluminoxane, tetraisobutyl-dialuminoxane,diethyl-aluminumethoxide, diisobutylaluminum chloride, methylaluminumdichloride, diethylaluminum chloride, ethylaluminum dichloride anddimethylaluminum chloride.

Non-limiting examples of suitable compounds includetetraethyldialuminoxane, methylaluminoxane, isobutylaluminoxane,tetraisobutyldialuminoxane, diethylaluminum ethoxide, diisobutylaluminumchloride, methylaluminum dichloride, diethylaluminum chloride,ethylaluminum dichloride and dimethylaluminum chloride.

Preferably, the co-catalyst is triethylaluminum. The molar ratio ofaluminum to titanium may be from about 5:1 to about 500:1 or from about10:1 to about 200:1 or from about 15:1 to about 150:1 or from about 20:1to about 100:1. The molar ratio of aluminum to titanium is preferablyabout 45:1.

The invention also relates to a process to make the catalyst system bycontacting a Ziegler-Natta type procatalyst, a co-catalyst and theexternal electron donor according to the present invention. Theprocatalyst, the co-catalyst and the external donor can be contacted inany way known to the skilled person in the art; and as also describedherein, more specifically as in the Examples.

The invention further relates to a process for making a polyolefin bycontacting an olefin with the catalyst system according to the presentinvention. The procatalyst, the co-catalyst, the external donor and theolefin can be contacted in any way known to the skilled person in theart; and as also described herein.

For instance, the external donor in the catalyst system according to thepresent invention can be complexed with the co-catalyst and mixed withthe procatalyst (pre-mix) prior to contact between the catalystcomposition and the olefin. The external donor can also be addedindependently to the polymerization reactor. The procatalyst, theco-catalyst, and the external donor can be mixed or otherwise combinedprior to addition to the polymerization reactor.

Contacting the olefin with the catalyst system according to the presentinvention can be done under standard polymerization conditions, known tothe skilled person in the art. See for example Pasquini, N. (ed.)“Polypropylene handbook” 2^(nd) edition, Carl Hanser Verlag Munich,2005. Chapter 6.2 and references cited therein.

The polymerization process may be a gas phase, a slurry or a bulkpolymerization process, operating in one or more than one reactor. Oneor more olefin monomers can be introduced in a polymerization reactor toreact with the catalyst composition and to form an olefin-based polymer(or a fluidized bed of polymer particles).

In the case of polymerization in a slurry (liquid phase), a dispersingagent is present. Suitable dispersing agents include for examplepropane, n-butane, isobutane, n-pentane, isopentane, hexane (e.g. iso-or n-), heptane (e.g. iso- or n-), octane, cyclohexane, benzene,toluene, xylene, liquid propylene and/or mixtures thereof. Thepolymerization such as for example the polymerization temperature andtime, monomer pressure, avoidance of contamination of catalyst, choiceof polymerization medium in slurry processes, the use of furtheringredients (like hydrogen) to control polymer molar mass, and otherconditions are well known to persons of skill in the art. Thepolymerization temperature may vary within wide limits and is, forexample for propylene polymerization, between 0° C. and 120° C.,preferably between 40° C. and 100° C. The pressure during (propylene)(co)polymerization is for instance between 0.1 and 6 MPa, preferablybetween 1-4 MPa.

Several types of polyolefins are prepared such as homopolyolefins,random copolymers and heterophasic polyolefin. The for latter, andespecially heterophasic polypropylene, the following is observed.

Heterophasic propylene copolymers are generally prepared in one or morereactors, by polymerization of propylene and optionally one or moreother olefins, for example ethylene, in the presence of a catalyst andsubsequent polymerization of a propylene-α-olefin mixture. The resultingpolymeric materials can show multiple phases (depending on monomerratio), but the specific morphology usually depends on the preparationmethod and monomer ratio. The heterophasic propylene copolymers employedin the process according to present invention can be produced using anyconventional technique known to the skilled person, for examplemultistage process polymerization, such as bulk polymerization, gasphase polymerization, slurry polymerization, solution polymerization orany combinations thereof. Any conventional catalyst systems, forexample, Ziegler-Natta or metallocene may be used. Such techniques andcatalysts are described, for example, in WO06/010414; Polypropylene andother Polyolefins, by Ser van der Ven, Studies in Polymer Science 7,Elsevier 1990; WO06/010414, U.S. Pat. No. 4,399,054 and U.S. Pat. No.4,472,524.

The molar mass of the polyolefin obtained during the polymerization canbe controlled by adding hydrogen or any other agent known to be suitablefor the purpose during the polymerization. The polymerization can becarried out in a continuous mode or batch-wise. Slurry-, bulk-, andgas-phase polymerization processes, multistage processes of each ofthese types of polymerization processes, or combinations of thedifferent types of polymerization processes in a multistage process arecontemplated herein. Preferably, the polymerization process is a singlestage gas phase process or a multistage, for instance a two-stage gasphase process, e.g. wherein in each stage a gas-phase process is used orincluding a separate (small) prepolymerization reactor.

Examples of gas-phase polymerization processes include both stirred bedreactors and fluidized bed reactor systems; such processes are wellknown in the art. Typical gas phase olefin polymerization reactorsystems typically comprise a reactor vessel to which an olefinmonomer(s) and a catalyst system can be added and which contain anagitated bed of growing polymer particles. Preferably the polymerizationprocess is a single stage gas phase process or a multistage, forinstance a 2-stage, gas phase process wherein in each stage a gas-phaseprocess is used.

As used herein, “gas phase polymerization” is the way of an ascendingfluidizing medium, the fluidizing medium containing one or moremonomers, in the presence of a catalyst through a fluidized bed ofpolymer particles maintained in a fluidized state by the fluidizingmedium optionally assisted by mechanical agitation. Examples of gasphase polymerization are fluid bed, horizontal stirred bed and verticalstirred bed.

“fluid-bed,” “fluidized,” or “fluidizing” is a gas-solid contactingprocess in which a bed of finely divided polymer particles is elevatedand agitated by a rising stream of gas optionally assisted by mechanicalstirring. In a “stirred bed” upwards gas velocity is lower than thefluidization threshold.

A typical gas-phase polymerization reactor (or gas phase reactor)include a vessel (i.e., the reactor), the fluidized bed, a productdischarge system and may include a mechanical stirrer, a distributionplate, inlet and outlet piping, a compressor, a cycle gas cooler or heatexchanger. The vessel may include a reaction zone and may include avelocity reduction zone, which is located above the reaction zone (viz.the bed). The fluidizing medium may include propylene gas and at leastone other gas such as an olefin and/or a carrier gas such as hydrogen ornitrogen. The contacting can occur by way of feeding the catalystcomposition into the polymerization reactor and introducing the olefininto the polymerization reactor. In an embodiment, the process includescontacting the olefin with a co-catalyst. The co-catalyst can be mixedwith the procatalyst (pre-mix) prior to the introduction of theprocatalyst into the polymerization reactor. The co-catalyst may be alsoadded to the polymerization reactor independently of the procatalyst.The independent introduction of the co-catalyst into the polymerizationreactor can occur (substantially) simultaneously with the procatalystfeed.

The olefin according to the invention may be selected from mono- anddi-olefins containing from 2 to 40 carbon atoms. Suitable olefinmonomers include alpha-olefins, such as ethylene, propylene,alpha-olefins having between 4 and 20 carbonatoms (viz. C4-20), such as1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-octene,1-decene, 1-dodecene and the like; C4-C20 diolefins, such as1,3-butadiene, 1,3-pentadiene, norbornadiene, 5-vinyl-2-norbornene(VNB), 1,4-hexadiene, 5-ethylidene-2-norbornene (ENB) anddicyclopentadiene; vinyl aromatic compounds having between 8 and 40carbon atoms (viz. C8-C40) including styrene, o-, m- andp-methylstyrene, divinylbenzene, vinylbiphenyl, vinylnapthalene; andhalogen-substituted C8-C40 vinyl aromatic compounds such aschlorostyrene and fluorostyrene.

Preferably, the olefin is propylene or a mixture of propylene andethylene, to result in a propylene-based polymer, such as propylenehomopolymer or propylene-olefin copolymer. The olefin may analpha-olefin having up to 10 carbon atoms, such as ethylene, butane,hexane, heptane, octene. A propylene copolymer is herein meant toinclude both so-called random copolymers which typically have relativelylow comonomer content, e.g. up to 10 mol. %, as well as so-called impactPP copolymers or heterophasic PP copolymers comprising higher comonomercontents, e.g. from 5 to 80 mol. %, more typically from 10 to 60 mol. %.The impact PP copolymers are actually blends of different propylenepolymers; such copolymers can be made in one or two reactors and can beblends of a first component of low comonomer content and highcrystallinity, and a second component of high comonomer content havinglow crystallinity or even rubbery properties. Such random and impactcopolymers are well-known to the skilled in the art. Apropylene-ethylene random copolymer may be produced in one reactor.Impact PP copolymers may be produced in two reactors: polypropylenehomopolymer may be produced in a first reactor; the content of the firstreactor is subsequently transferred to a second reactor into whichethylene (and optionally propylene) is introduced. This results inproduction of a propylene-ethylene copolymer (i.e. an impact copolymer)in the second reactor.

The present invention also relates to a polyolefin, preferably apolypropylene obtained or obtainable by a process, comprising contactingan olefin, preferably propylene or a mixture of propylene and ethylenewith the procatalyst according to the present invention. The termspolypropylene and propylene-based polymer are used hereininterchangeable. The polypropylene may be a propylene homopolymer or amixture of propylene and ethylene, such as a propylene-based copolymer,e.g. heterophasic propylene-olefin copolymer; random propylene-olefincopolymer, preferably the olefin in the propylene-based copolymers beinga C2, or C4-C6 olefin, such as ethylene, butylene, pentene or hexene.Such propylene-based (co)polymers are known to the skilled person in theart; they are also described herein above.

The present invention also relates to a polyolefin, preferably apropylene-based polymer obtained or obtainable by a process as describedherein above, comprising contacting propylene or a mixture of propyleneand ethylene with a catalyst system according to the present invention.

In one embodiment the present invention relates to the production of ahomopolymer of polypropylene. For such a polymer, properties such asisotacticity and stiffness and emission may be important.

“comonomer content” or “C2 content” in the context of the presentinvention means the weight percentage (wt. %) of respectively comonomeror ethylene incorporated incorporated into the total polymer weightobtained and measured with FT-IR. The FT-IR method was calibrated usingNMR data.

MFR is preferably from about 0.01 g/10 min to about 2000 g/10 min, orfrom about 0.01 g/10 min to about 1000 g/10 min; or from about 0.1 g/10min to about 500 g/10 min, or from about 0.5 g/10 min to about 150 g/10min, or from about 1 g/10 min to about 100 g/10 min.

The olefin polymer obtained in the present invention is considered to bea thermoplastic polymer. The thermoplastic polymer composition accordingto the invention may also contain one or more of usual additives, likethose mentioned above, including stabilizers, e.g. heat stabilizers,anti-oxidants, UV stabilizers; colorants, like pigments and dyes;clarifiers; surface tension modifiers; lubricants; flame-retardants;mold-release agents; flow improving agents; plasticizers; anti-staticagents; impact modifiers; blowing agents; fillers and reinforcingagents; and/or components that enhance interfacial bonding betweenpolymer and filler, such as a maleated polypropylene, in case thethermoplastic polymer is a polypropylene composition. The skilled personcan readily select any suitable combination of additives and additiveamounts without undue experimentation.

The amount of additives depends on their type and function; typically isof from 0 to about 30 wt. %; preferably of from 0 to about 20 wt. %;more preferably of from 0 to about 10 wt. % and most preferably of from0 to about 5 wt. % based on the total composition. The sum of allcomponents added in a process to form the polyolefins, preferably thepropylene-base polymers or compositions thereof should add up to 100 wt.%.

The thermoplastic polymer composition of the invention may be obtainedby mixing one or more of the thermoplastic polymers with one or moreadditives by using any suitable means.

Preferably, the thermoplastic polymer composition of the invention ismade in a form that allows easy processing into a shaped article in asubsequent step, like in pellet or granular form. The composition can bea mixture of different particles or pellets; like a blend of athermoplastic polymer and a master batch of nucleating agentcomposition, or a blend of pellets of a thermoplastic polymer comprisingone of the two nucleating agents and a particulate comprising the othernucleating agent, possibly pellets of a thermoplastic polymer comprisingsaid other nucleating agent. Preferably, the thermoplastic polymercomposition of the invention is in pellet or granular form as obtainedby mixing all components in an apparatus like an extruder; the advantagebeing a composition with homogeneous and well-defined concentrations ofthe nucleating agents (and other components).

The invention also relates to the use of the polyolefins, preferably thepropylene-based polymers (also called polypropylenes) according to theinvention in injection molding, blow molding, extrusion molding,compression molding, casting, thin-walled injection molding, etc. forexample in food contact applications.

Furthermore, the invention relates to a shaped article comprising thepolyolefin, preferably the propylene-based polymer according to thepresent invention.

The polyolefin, preferably the propylene-based polymer according to thepresent invention may be transformed into shaped (semi)-finishedarticles using a variety of processing techniques. Examples of suitableprocessing techniques include injection molding, injection compressionmolding, thin wall injection molding, extrusion, and extrusioncompression molding. Injection molding is widely used to producearticles such as for example caps and closures, batteries, pails,containers, automotive exterior parts like bumpers, automotive interiorparts like instrument panels, or automotive parts under the bonnet.Extrusion is for example widely used to produce articles, such as rods,sheets, films and pipes. Thin wall injection molding may for example beused to make thin wall packaging applications both for food and non-foodsegments. This includes pails and containers and yellow fats/margarinetubs and dairy cups.

It is noted that the invention relates to all possible combinations offeatures recited in the claims. Features described in the descriptionmay further be combined.

Although the invention has been described in detail for purposes ofillustration, it is understood that such detail is solely for thatpurpose and variations can be made therein by those skilled in the artwithout departing from the spirit and scope of the invention as definedin the claims.

It is further noted that the invention relates to all possiblecombinations of features described herein, preferred in particular arethose combinations of features that are present in the claims.

It is further noted that the term ‘comprising’ does not exclude thepresence of other elements. However, it is also to be understood that adescription on a product comprising certain components also discloses aproduct consisting of these components. Similarly, it is also to beunderstood that a description on a process comprising certain steps alsodiscloses a process consisting of these steps.

The invention will be further elucidated with the following exampleswithout being limited hereto.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 (FIG. 1) shows the oligomer content versus the log(MFR) ofpropylene homopolymers produced using catalyst I and different externaldonors.

FIG. 2 (FIG. 2) shows the oligomer content versus the log(MFR) ofpropylene homopolymers produced using catalyst II and different externaldonors.

EXPERIMENTAL Procatalyst I

Procatalyst I is prepared according to the method disclosed in U.S. Pat.No. 4,866,022. This patent discloses a catalyst component comprising aproduct formed by: A. forming a solution of a magnesium-containingspecies from a magnesium carbonate or a magnesium carboxylate; B.precipitating solid particles from such magnesium-containing solution bytreatment with a transition metal halide and an organosilane having aformula: R_(n)SiR′_(4-n), wherein n=0 to 4 and wherein R is hydrogen oran alkyl, a haloalkyl or aryl radical containing one to about ten carbonatoms or a halosilyl radical or haloalkylsilyl radical containing one toabout eight carbon atoms, and R′ is OR or a halogen: C. reprecipitatingsuch solid particles from a mixture containing a cyclic ether; and D.treating the reprecipitated particles with a transition metal compoundand an electron donor. This process for preparing a catalyst isincorporated into the present application by reference.

Procatalyst II

Procatalyst II was prepared according to the method described in U.S.Pat. No. 5,093,415 of Dow. This patent discloses an improved process toprepare a catalyst. Said process includes a reaction between titaniumtetrachloride, diisobutyl phthalate, and magnesium diethoxide to obtaina solid material. This solid material is then slurried with titaniumtetrachloride in a solvent and phthaloyl chloride is added. The reactionmixture is heated to obtain a solid material which is reslurried in asolvent with titanium tetrachloride. Again this was heated and a solidcollected. Once again the solid was reslurried once again in a solutionof titanium tetrachloride to obtain a catalyst.

Procatalyst III A. Grignard Formation Step

A stirred flask, fitted with a reflux condenser and a funnel, was filledwith magnesium powder (24.3 g). The flask was brought under nitrogen.The magnesium was heated at 80° C. for 1 hour, after which dibutyl ether(DBE, 150 ml), iodine (0.03 g) and n-chlorobutane (4 ml) weresuccessively added. After the colour of the iodine had disappeared, thetemperature was raised to 80° C. and a mixture of n-chlorobutane (110ml) and dibutyl ether (750 ml) was slowly added for 2.5 hours. Thereaction mixture was stirred for another 3 hours at 80° C. Then thestirring and heating were stopped and the small amount of solid materialwas allowed to settle for 24 hours. By decanting the colorless solutionabove the precipitate, a solution of butylmagnesiumchloride (reactionproduct of step A) with a concentration of 1.0 mol Mg/I was obtained.

B. Preparation of the Intermediate Reaction Product

250 mL of dibutyl ether was introduced to a 1 L reactor fitted with apropeller stirrer and two baffles. The reactor was thermostated at 35°C. and the stirrer speed was kept at 200 rpm. Then a cooled (to 15° C.)360 mL solution of the Grignard reaction product as prepared in A and180 ml of a cooled (to 15° C.) solution of 38 ml of tetraethoxysilane(TES) in 142 ml of DBE were dosed into the reactor for 400 min. withpreliminary mixing in a minimixer of 0.15 ml volume, which was cooled to15° C. by means of cold water circulating in the minimixer jacket. Thepremixing time was 18 seconds in the minimixer and the connecting tubebetween the minimixer and the reactor. The stirring speed in theminimixer was 1000 rpm. On the dosing completion, the reaction mixturewas kept at 35° C. for 0.5 hours. Then the reactor was heated to 60° C.and kept at this temperature for 1 hour. Then the stirring was stoppedand the solid substance was allowed to settle. The supernatant wasremoved by decanting. The solid substance was washed three times using300 ml of heptane. As a result, a white solid reaction product wasobtained and suspended in 200 ml of heptane.

Under an inert nitrogen atmosphere at 20° C. a 250 ml glass flaskequipped with a mechanical agitator is filled with a slurry of 5 g ofthe reaction product of step B dispersed in 60 ml of heptane.Subsequently, a solution of 0.86 ml methanol (MeOH/Mg=0.5 mol) in 20 mlheptane is dosed under stirring during 1 hour. After keeping thereaction mixture at 200° C. for 30 minutes the slurry was slowly allowedto warm up to 300° C. for 30 min and kept at that temperature foranother 2 hours. Finally the supernatant liquid is decanted from thesolid reaction product which was washed once with 90 ml of heptane at300° C.

C. Preparation of the Procatalyst

A reactor was brought under nitrogen and 125 ml of titaniumtetrachloride was added to it. The reactor was heated to 90° C. and asuspension, containing about 5.5 g of the support obtained in step C in15 ml of heptane, was added to it under stirring. The reaction mixturewas kept at 90° C. for 10 min. Then ethyl benzoate was added (EB/Mg=0.15molar ratio). The reaction mixture was kept for 60 min. Then thestirring was stopped and the solid substance was allowed to settle. Thesupernatant was removed by decanting, after which the solid product waswashed with chlorobenzene (125 ml) at 90° C. for 20 min. The washingsolution was removed by decanting, after which a mixture of titaniumtetrachloride (62.5 ml) and chlorobenzene (62.5 ml) was added. Thereaction mixture was kept at 90° C. for 30 min. After which the stirringwas stopped and the solid substance was allowed to settle. Thesupernatant was removed by decanting, after which a mixture of titaniumtetrachloride (62.5 ml) and chlorobenzene (62.5 ml) was added. Thendi-n-butyl phthalate (DBP) (DBP/Mg=0.15 molar ratio) in 3 ml ofchlorobenzene was added to reactor and the temperature of reactionmixture was increased to 115° C. The reaction mixture was kept at 115°C. for 30 min. After which the stirring was stopped and the solidsubstance was allowed to settle. The supernatant was removed bydecanting, after which a mixture of titanium tetrachloride (62.5 ml) andchlorobenzene (62.5 ml) was added. The reaction mixture was kept at 115°C. for 30 min, after which the solid substance was allowed to settle.The supernatant was removed by decanting and the solid was washed fivetimes using 150 ml of heptane at 600° C., after which the procatalystIII, suspended in heptane, was obtained.

Batch Propylene Polymerization Experiments

Propylene polymerization experiments (Table 1) were performed usingprocatalysts I, II and III described above. Triethylaluminium was usedas co-catalyst, and several external electron donors (ED) were employed.Experiments were performed at different H2/C3 molar ratios. Examplesdenoted with CE are comparative examples not according to the presentinvention.

The copolymerization of propylene and ethylene was carried out in astainless steel reactor with a volume of 1800 mL. Under a nitrogenatmosphere, the co-catalyst (TEAL) and procatalyst synthesized accordingto the procedure described above and the external electron donor weredosed to the reactor as heptane solutions or slurries. 10-15 mg ofprocatalyst were employed. The molar ratio of co-catalyst to titanium(from the procatalyst) was set to 160, and the Si/Ti ratio was set to 9.During this dosing, the reactor temperature was maintained below 30° C.Subsequently, the reactor was pressurized using a set ratio of propyleneand hydrogen, and the temperature and pressure were raised to itssetpoint (70° C. and 20 barg). After the pressure setpoint has beenreached, the polymerization was continued for 60 minutes. During thepolymerization reaction the gas cap composition of propylene andhydrogen was controlled using mass flow meters and online-GC control.After reaching the polymerization time the reactor was depressurized andcooled to ambient conditions. The propylene polymer so obtained wasremoved from the reactor and stored in aluminium bags. The polymerpowders were premixed with the additives (amounts in final product: 2000ppm heat stabilizer, 2000 ppm process stabilizer and 900 ppm Castearate) and extruded into strands using a mini compounder.

Abbreviations and measuring methods:

With C-donor is meant: cyclohexylmethyldimethoxysilane.

With D-donor is meant: dicyclopentyldimethoxysilane.

-   -   PP yield, kg/g cat is the amount of polypropylene obtained per        gram of catalyst system.    -   H2/C3 is the molar ratio of hydrogen to propylene in the gas cap        of the reactor, measured by on-line gas chromatography.    -   Oligomer content refers to the amount in ppm in a polymer sample        of the C6-C33 hydrocarbon oligomers, which typically originate        from the low molecular weight material in the polymer        composition. Thermal desorption of these oligomers from polymer        samples was performed using a Markes TD100. A weighed off sample        of 50-100 mg of the produced polymer strand was loaded into an        inert metal tube. This tube was briefly purged at room        temperature using helium. The tube was heated to 200° C. and a        carrier gas was passed over the molten polymer sample for 30        minutes. Upon exiting the tube, the carrier gas was passed        through a cold trap, condensing the volatile components        liberated from the polymer. Subsequently, the cold trap was        rapidly heated to 250° C. and the volatiles were injected into a        Agilent GC, using a CP-SIL5 GC column (25 meter) for separation        of the individual components. Identification of the components        was performed using a MS detector and quantification was        performed using a FID detector.

TABLE 1 polymerization and analysis data Oligomer Exp # External PPYield MFR H₂/C₃ content nr Catalyst Donor Kg/g cat dg/min (mol:mol) ppmCE1 I DiPDMS 11.77 44.84 0.0647 1735 CE2 I DiPDMS 13.8 27.92 0.0434 12911 I nPTES 7.38 38.68 0.0226 950 CE3 I DiPDMS 15.79 74.71 0.0814 2286 CE4I C-Donor 13.63 65.96 0.0706 2036 CE5 I D-Donor 18.09 63.79 0.1498 22002 I nPTES 11.7 72.16 0.0238 1206 CE6 I DiPDMS 12.09 127.9 0.1271 2415 3I nPTES 9.25 148.7 0.0476 1536 4 I nPTES 5.69 293.0 0.0804 1834 CE7 IIDiPDMS 16.67 69.54 0.0606 1487 CE8 II C-Donor 14.89 71.22 0.0622 1521CE9 II D-Donor 19.41 58.26 0.1233 2101 5 II nPTES 13.72 66.65 0.0168 878CE10 II nPTMS 17.40 75.24 0.0445 1254 CE11 II DiPDMS 15.15 112.1 0.08211927 6 II nPTES 10.08 125.5 0.0336 755 CE12 II nPTMS 17.46 116.1 0.06021711 CE13 III DiPDMS 22.71 44.60 0.0582 1589 CE14 III nPTMS 11.57 40.900.0396 1266

From the two figures FIG. 1 and FIG. 2, and the data from Tale 1 above,it is clear that with catalysts I and II, the use of nPTES as externaldonor results in materials with lower oligomer content compared tomaterials with similar MFR-values, made using other donors. Also forcatalyst II, the material produced using nPTMS shows higher oligomercontent than a material with similar range for the MFR value producedusing nPTES as external donor. This can be observed when comparing CE12with Example 6 and when comparing CE10 with Example 5.

Therefore, with the external donor of Formula IV: nPTES, it is possibleto obtain polypropylene (homopolymers) having lower emissions (as shownby the lower oligomer content) than polypropylene having similar MFRvalues produced with a different external donor.

In another aspect therefore, the invention relates to a propylene-basedpolymer, such as propylene homopolymer or propylene-olefin copolymer,for example propylene-ethylene copolymer, for example having an ethylenecontent based on propylene-ethylene copolymer in the range from 1 to 10wt. %, for example in the range from 1 to 8, for example in the rangefrom 1 to 5 wt. %; or heterophasic propylene copolymers,

-   -   having a melt flow index in the range from 30 to 1000, for        example from 40 to 500 as determined according to the method        discussed above;    -   a ratio of the oligomer content in ppm to the log(melt flow        index) of less than 1650, for example of less than 1550, wherein        the oligomer content is measured according to the method        discussed above;    -   wherein at log (MFR)=2.1, the oligomer content is less than 1850        ppm, wherein this is determined according to the method        discussed above.

1. A process for the preparation of a catalyst system suitable forolefin polymerization, said process comprising: providing amagnesium-based support; optionally activating said magnesium-basedsupport; contacting said magnesium-based support with a Ziegler-Nattatype catalytic species, and optionally one or more internal electrondonors to yield a procatalyst, and contacting said procatalyst with aco-catalyst and at least one external donor; wherein the at least oneexternal electron donor is n-propyltriethoxysilane.
 2. The processaccording to claim 1, wherein the process comprises: i) preparing amagnesium-based support by heating a carbonated magnesium compound ofthe formula MgR′R″xCO₂ wherein R′ is an alkoxide or aryloxide group, R″is an alkoxide group, aryloxide group or halogen, and x has a valuebetween about 0.1 and 2.0 to a temperature above 100° C. for a period oftime sufficient to cause complete loss of CO₂; ii) contacting theresulting product with a halide of tetravalent titanium as theZiegler-Natta type catalytic species in the presence of ahalohydrocarbon and an internal electron donor; and iii) contacting theresulting halogenated product with a tetravalent titanium halide; andcontacting said product obtained with a co-catalyst and at least oneexternal donor; wherein the at least one external electron donor isn-propyltriethoxysilane.
 3. The process according to claim 1, whereinthe process comprises preparing a magnesium-based support byhalogenating a magnesium compound of the formula MgR′R″, wherein R′ andR″ are alkoxide groups containing from 1 to 8 carbon atoms, withtitanium tetrachloride, in the presence of: 1) an aromatichalohydrocarbon containing from 6 to 12 carbon atoms and from 1 to 2halogen atoms and; 2) a polycarboxylic acid ester derived from abranched or 4 of 12 unbranched monohydric alcohol containing from 1 to12 carbon atoms, and 3) a monocyclic or polycyclic aromatic compoundcontaining from 8 to 20 carbon atoms and two carboxyl groups which areattached to ortho carbon atoms of the ring structure and contacting theproduct obtained with a co-catalyst and at least one external donor;wherein the at least one external electron donor isn-propyltriethoxysilane.
 4. The process according to claim 1, whereinthe process comprises: preparing the magnesium-based support by forminga solution of a magnesium-containing species from a magnesium carbonateor a magnesium carboxylate, precipitating solid particles from suchmagnesium-containing solution by treatment with a transition metalhalide and an organosilane having a formula: RnSiR′₄″n, wherein n=0 to 4and wherein R is hydrogen or an alkyl, a haloalkyl or aryl radicalcontaining one to about ten carbon atoms or a halosilyl radical orhaloalkylsilyl radical containing one to about eight carbon atoms, andR′ is OR or a halogen, reprecipitating such solid particles from amixture containing a cyclic ether, and contacting the product obtainedwith a co-catalyst and at least one external donor; wherein the at leastone external electron donor is n-propyltriethoxysilane.
 5. The processaccording to claim 1, wherein the process comprises: A) providing saidprocatalyst obtainable via a process comprising: i) contacting acompound R⁴ _(z)MgX⁴ _(2-z) with an alkoxy- or aryloxy-containing silanecompound to give a first intermediate reaction product, being a solidMg(OR′)_(x)X¹ _(2-x), wherein: R⁴ is the same as R¹ being a linear,branched or cyclic hydrocarbyl group independently selected from alkyl,alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one ormore combinations thereof; wherein said hydrocarbyl group is substitutedor unsubstituted, optionally comprises one or more heteroatoms and hasbetween 1 and 20 carbon atoms; X⁴ and X¹ are each independently selectedfrom fluoride (F⁻), chloride (Cl⁻), bromide (Br⁻) or iodide (I⁻); z isin a range of larger than 0 and smaller than 2, being 0<z<2; ii)optionally contacting the solid Mg(OR¹)_(x)X_(2-x) obtained in step i)with at least one activating compound selected from activating electrondonor compounds and metal alkoxide compounds of formulaM¹(OR²)_(v-w)(OR³)_(w) or M²(OR²)_(v-w)(R³)_(w), to obtain a secondintermediate product; wherein M¹ is a metal selected from Ti, Zr, Hf, Alor Si; M² is a metal being Si; v is the valency of M¹ or M²; R² and R³are each a linear, branched or cyclic hydrocarbyl group independentlyselected from alkyl, alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylarylgroups, and one or more combinations thereof; wherein said hydrocarbylgroup substituted or unsubstituted, optionally comprises one or moreheteroatoms, and has between 1 and 20 carbon atoms; iii) contacting thefirst or second intermediate reaction product, obtained respectively instep i) or ii), with a halogen-containing Ti-compound and optionally aninternal electron donor to obtain said procatalyst; B) contacting saidprocatalyst with a co-catalyst and at least one external electron donorbeing n-propyltriethoxysilane.
 6. The process according to claim 1,wherein the process is essentially phthalate free.
 7. The processaccording to claim 1, wherein an internal donor is selected fromaminobenzoates represented by Formula XI:

wherein: R⁸⁰, R⁸¹, R⁸², R⁸³, R⁸⁴, R⁸⁵, and R⁸⁶ are independentlyselected from hydrogen, C₁-C₁₀ straight and branched alkyl; C₃-C₁₀cycloalkyl; C₆-C₁₀ aryl; and C₇-C₁₀ alkaryl and aralkyl group; whereinR₈₁ and R₈₂ is each a hydrogen atom and R₈₃, R₈₄, R₈₅ and R₈₆ areindependently selected from a group consisting of C₁-C₁₀ straight andbranched alkyl; C₃-C₁₀ cycloalkyl; C₆-C₁₀ aryl; and C₇-C₁₀ alkaryl andaralkyl group; wherein when one of R₈₃ and R₈₄ and one of R₈₅ and R₈₆has at least one carbon atom, then the other one of R₈₃ and R₈₄ and ofR₈₅ and R₈₆ is each a hydrogen atom; wherein R₈₇ is selected from agroup consisting of hydrogen, methyl, ethyl, propyl, isopropyl, butyl,t-butyl, phenyl, benzyl, substituted benzyl and halophenyl group; andwherein R₈₈ is selected from the group consisting of C₆-C₁₀ aryl; andC₇-C₁₀ alkaryl and aralkyl group.
 8. Process according to claim 1,wherein the internal electron donor is selected from4-[benzoyl(methyl)amino]pentan-2-yl benzoate;2,2,6,6-tetramethyl-5-(methylamino)heptan-3-ol dibenzoate; 4-[benzoyl(ethyl)amino]pentan-2-yl benzoate, 4-(methylamino)pentan-2-yl bis(4-methoxy)benzoate); 3-[benzoyl(cyclohexyl)amino]-1-phenylbutylbenzoate; 3-[benzoyl(propan-2-yl)amino]-1-phenylbutyl;4-[benzoyl(methyl)amino]-1,1,1-trifluoropentan-2-yl;3-(methylamino)-1,3-diphenylpropan-1-ol dibenzoate;3-(methyl)amino-propan-1-ol dibenzoate;3-(methyl)amino-2,2-dimethylpropan-1-ol dibenzoate, and4-(methylamino)pentan-2-yl bis-(4-methoxy)benzoate).
 9. Processaccording to claim 1, wherein the internal electron donor is activatedby an activator.
 10. A catalyst system obtained by the process ofclaim
 1. 11. A process for preparing a polyolefin, comprising contactingat least one olefin with the catalyst system of claim
 10. 12. Apolyolefin obtained by the process of claim
 11. 13. A propylenehomopolymer, a propylene-olefin copolymer, or a heterophasic propylenecopolymer characterized by: having a melt flow index in the range from30 to 1000 as determined according to ISO 1133: 2005 at 230° C. with2.16 kg load; a ratio of an oligomer content in ppm to the log(MFR) ofless than 1650; wherein the oligomer content is the amount of C6-C33hydrocarbon oligomers in ppm in the polymer and is determined by thermaldesorption of these oligomers from the polymer samples using anautomated thermal desorption unit wherein a weighed sample of 50-100 mgof the polymer is loaded into an inert metal tube; which tube is brieflypurged at room temperature using helium and subsequently heated to 200°C., and then a carrier gas is passed over the molten polymer sample for30 minutes; and upon exiting the tube, the carrier gas is passed througha cold trap, condensing the volatile components liberated from thepolymer and subsequently, the cold trap is rapidly heated to 250° C. andthe volatiles are injected into a gas chromatography fitted with adimethylpolysiloxane stationary phase column of 25 meter length forseparation of the individual components, which were identified using amass spectrometer detector and quantified using a flame ionizationdetector; the oligomer content being less than 1850 ppm at log(MFR)=2.1,as determined by making a calibration line of the oligomer content ofthe polymer versus the log(MFR), wherein the polymer of the calibrationline is produced using a Ziegler Natta catalyst and the same externaldonor.
 14. A shaped article comprising the polyolefin according to claim12.
 15. The process according to claim 9, wherein the internal electrondonor is activated by an activator, wherein the activator is a benzamideaccording to formula X,

wherein, R⁷⁰ and R⁷¹ are each independently selected from hydrogen or analkyl, preferably an alkyl having between 1 and 6 carbon atoms: R⁷²,R⁷³, R⁷⁴, R⁷⁵, R⁷⁶ are each independently selected from hydrogen, aheteroatom such as a halide, or a hydrocarbyl group selected from alkyl,alkenyl, aryl, aralkyl, alkoxycarbonyl or alkylaryl groups, and one ormore combinations thereof.
 16. The process according to claim 15,wherein the benzamide according to formula X is present in theprocatalyst in an amount from 0.1 to 4 wt. % as determined using HPLC.17. The process according to claim 8, wherein the internal electrondonor is activated by an activator, wherein the activator isN,N-dimethylbenzamide.
 18. A catalyst system obtained by the process ofclaim
 17. 19. A process for preparing a polyolefin, comprisingcontacting at least one olefin with the catalyst system of claim
 17. 20.The propylene homopolymer, the propylene-olefin copolymer, or theheterophasic propylene copolymer, wherein the melt flow index is in therange from 40 to 500, and the ratio of the oligomer content in ppm tothe log(MFR) is less than 1550.